Etymology of Earth science words and phrases

The origins of words, prefixes, suffixes, abbreviations, names, acronyms, and terms commonly used in geology, with an emphasis on sedimentology, stratigraphy, paleontology, basin analysis, structure, geodynamics, geochemistry, and the occasional digression to planetary bodies.

Many words have multiple meanings or contexts; I tend to focus on those origins pertinent to the science.

Information has been extracted from many sources

• the Gutenberg Project (free ebooks),
• The Biodiversity Heritage Library (free access),
• Online Etymology Dictionary
• Wikipedia.
• Online Oxford English Dictionary (OED) (paywalled)
• An Etymological Dictionary of Astronomy and Astrophysics
• The concise Dictionary of Middle English by Rev. A. L. Mayhew and Rev. Walter Skeat
• A Concise Anglo-Saxon Dictionary
• The Internet Archive.
• Individual publications scattered throughout the scientific and humanities literature.

Word elements – Prefixes and suffixes are indicated with a hyphen (-), as in -ate, or aqua-.

A rough guide to language designations

Indo-European languages: Many European (old Germanic), Baltic and Slavik, Roman, Celtic, and Indo-Iranian languages have common attributes, that may have evolved from one Indo-European root language(s). The term Indo-European was introduced in 1816 by Franz Bopp.

The Indo-European language is thought to have been derived from a Proto-Indo-European (PIE) base about 5000 years ago. Many of the words we use can be traced to these early root languages. Possible language branches and families are shown in the diagram below (From University of Ottawa; Compendium of Language Management in Canada)

Latin was one of the Roman branches of the Indo-European languages. Old, or archaic Latin is pre- 100-75 BCE. Classical Latin developed thereafter.

Vulgar Latin was the colloquial or vernacular form although the distinction from Classical Latin is commonly vague.

Old English: Anglo-Saxon vocabulary to about 1150 CE. Beowulf is from this period.

Middle English: Mainly after 1066 until about 1450 – 1500 (the time of Chaucer). It took a while after King Harold eyed the arrow (1066) for Norman French to be absorbed into spoken-written English.

Proto-German Possibly from PIE, from about 5^th C BCE to 5^th CE. 

Old High German is the period 500/750 to 1050 CE, about the same time as Anglo-Saxon.

Old French mostly northern France between the 8^th C and 14^th C.

Preamble

The focus of my list is on the ‘soft rock’ side of Earth Science – sedimentology, stratigraphy, paleontology (without the digraph ae), basins, geochemistry, with digressions to structure, geodynamics, and the occasional planetary entry.

There are more than a million words in the English language – the list includes technical, scientific, and archaic words. The Oxford English Dictionary lists about 600,000 of them of which about 170,000 are in reasonably common use. Hundreds of new words are added each year. Individual vocabularies are wide ranging, with some estimates indicating an average 20,000 to 30,000. My listing is a tiny fraction of the language.

English language continues to evolve. It has never been afraid to borrow or steal from other languages. Its roots span thousands of years that encompass some of the earliest elements of Proto-Indo-European (PIE), and all the PIE languages that evolved from this: ancient Greek, Roman (old, vernacular, and classical Latin), Anglo-Saxon (Old English) that morphed over a few decades to Middle English following King Harold’s eye-catching act of hubris, multiple invasions over the centuries (including early Norse), plus the language ramifications of religious, political, scientific, and social upheavals.

 Although non-scientific folk may view scientific jargon as remote or incomprehensible, there is actually nothing magical or mysterious about any of it – all the words and expressions we use are borrowed from common language.

Etymologies

About: From Old English (pre-1150) abutan thence Middle English aboute and the adverb abouten meaning enveloping, nearby, to that place. By the 13^th C it also meant around. Other Middle English spelling are abuten, abuuten, abuton, abute.

Above: From Old English abufan and onbufan thence Middle English abouen meaning over, upper side, higher, Additional Middle English spellings are aboue, abufen, abuuen, abowen, abone, oboven, obowen, oboune.

Abyss: From the Greek abyssos meaning bottomless, unfathomable, and Latin abyssimum, and abyssus. Middle English form abyme is probably a variation from the Old French abime. From which we get abyssal (water depths) and later 17^th C abysmal.

Acceleration: From the Latin celer meaning swift or fast, and celerare meaning to quicken, combined into accelerationem (noun), and also Middle French acceleration. OED indicates the earliest use was 1490 (end of Middle English period). In Italian it means ‘addition of speed’ – used by Galileo to describe the motion of projectiles and falling bodies (in Two New Sciences, 1638). The concept was elaborated and quantified dimensionally by Newton in his Principia in 1687.

A.D. Literally Anno Domini, introduced by Dionysius Exiguus, a Christian monk in 525 (A.D./C.E.) – originally as Anni Domini Nostri Jesu Christi, or the time since Jesus’ incarnation. It has been replaced by the more neutral abbreviation C.E. (Common Era), a phrase used during the enlightenment for historical dates (e.g., Johannes Kepler).  

Addition: From the Latin addere meaning to join or add, that is made up word elements ad (the preposition to) and -dere meaning to put in place (from the verb dare meaning to give), also forming the noun additionem (addition). Thence Old French adition meaning increase, borrowed by Middle English as addicioun (late 14^th C). In arithmetic, the plus sign + is a Middle English graphical redrawing of the Latin et meaning ‘and’.

+ (plus sign): In arithmetic, the plus sign, +, also known as the Greek Cross, is probably a late Middle English graphical redrawing of the Latin et meaning ‘and’. The sin is probably the most important of all mathematical operators – even counting is basically an act of addition. It appears to have been used as short-hand for addition in both mathematical and textual contexts. One of the earliest records of its use in English is Johannes Widmann (1462-1498) who published in 1489 Behende und hübsche Rechenung auff allen Kauffmanschafft (“Nimble and neat calculation in all trades”), also known as Mercantile Arithmetic. He also is credited with the first use of the minus sign (-). Widmann did not invent the arithmetic form of addition – that is attributed to the author of the 3^rd – 4^th C Bakhshilli (or Bakhshali) manuscript.

-æ-: The squished letter derives from Latin and Greek digraphs that became common in Old English to enable pronunciation somewhere between the two vowels a and e in Latin, as in æfter (after) and ǣghwider (in all directions). Usage was far less common in Middle English, (e.g., as in æhte – eight); it was usually replaced by -a-. However, there was a resurgence of use in the 16^th C. It is now regarded as archaic and modern usage replaces most occurrences with an -a-. Usage does linger in some scientific words – British English still use Palæo as in palæontology, when most other English writers use paleo.

Aeolian – Eolian: From the Greek aiolos meaning shifting or changing, and Latin Aeolus who was the Roman God of wind. Hence its geomorphic-geologic meaning of wind-blown processes. Both spellings are correct although the ae- form more closely follows the Latin. Not in common use by early-mid 19^th C geologists like James Hutton  or Lyell, but later by Archibald Geikie 1881 who used eolian in his Prehistoric Europe – A Geological Sketch and in his Text-book of Geology (1882).   Its use increases from early 20^th C.

Airy isostasy: Named after Astronomer Royal George Airy, who demonstrated that gravity anomalies could be explained by deficiencies or excesses of mass in crustal blocks. His model of the crust used floating icebergs and Archimedes principle of hydrostatic pressure as analogies. In the Airy model, all crustal blocks that float on the mantle, have different heights or thicknesses but the same densities.  The depth of compensation, at which lithostatic pressures beneath all crustal blocks are equal, is located at the base of the deepest block (cf. the Pratt model).

Albeit: Chaucer’s use of ‘al were it’ (e.g., The Monks Tale) is the past tense of the later Middle English al be it, or altogether be it, that has contracted to albeit. From Old English eall meaning every, all, entire, and Old German al.

-ality: Common word element, also written as –alty. From the Latin word element –al that converts nouns to adjectives, and the Latin word element –ity that in Middle English was written -ite, and Old French -ete. As in commonality, finality, duality.

All models are wrong…: “All models are wrong, some are useful” is a now famous 1987 quote of British statistician George Box. Basically, he was stating that we should not be looking at correctness in models, but at their usefulness. The phrase is commonly repeated without the clause, which is a misrepresentation of what Box intended.  Empirical Model-Building and Response Surfaces – George E. P. Box and Norman R. Draper, Wiley, 1987.

Allo-: From Greek allos meaning other than or different. In a geological context it usually means outside or external. As in allochthonous, allogenic.

Allocyclic: From Greek allos. The geological context of process forcing by external agents or forces is late 19^th C. It’s use in geological publications increased markedly following James R. Beerbower’s 1964 paper where autocyclic and allocyclic are defined.

Alti-: A word element from the Latin altus meaning grown or high. When combined with word elements like -tude it forms the noun altitude. Similarly, altimeter.

Ammonite: From the Greek God Amun who was depicted either as a ram’s head or just his horns. The fossils were identified as Amun’s horns, later renamed Ammon. Pliny the Elder (CE 23-24 to 79) referred to the fossil forms as Hammonis cornua, and apparently recognised them as ancient life forms (long before da Vinci and other Renaissance icons). From a taxonomic perspective, it was German naturalist Johann Philipp Breyne who in 1732 applied the name Ammonite to a subclass of “many chambered molluscs”; Karl Alfred von Zittel (1884) applied the subclass name Ammonoidea that is used today. (see Spencer Daniel)

Amygdule: From the Greek amygdalo and Latin amygdala both of which refer to almonds. The geological meaning refers to the shape of an almond, although shapes are variable. Amygdules are cavities in (mostly) basaltic rocks that have been filled with secondary minerals like zeolite, calcite, or chlorite. The original cavities were gas-filled vesicles. James Hutton (1795) discusses the presence of mineral-filled amygdaloides in trap-rock (a name commonly used for basalt or diabase) and whin-stone “These are the agates, calcedonies, calcareous and zeolite nodules, which are found produced in our whin-stone or subterraneous lavas, that is, the amygdaloides of Crondstedt.”

Analysis: From Greek analysis and used by Aristotle in his Analytica meaning solutions to problems by breaking into component statements or to simplify, written about 350 BCE. Later in Medieval Latin analysis. Isaac Newton’s Principia (1687) frequently uses the words analysin (singular of analysis), analytici, analytice. Also Leonhard Euler in 1748 in Introductio in analysin infinitorum (Introduction to the Analysis of the Infinite). Also analyze or analyse, analytical.

-ance: A word element that transforms verbs to nouns – has the same origin as -ence, from the Latin -antia and -entia, to Old French, then borrowed by Old and Middle English, initially conforming to the Latin vowel -a or -e, but became fairly muddled in later English, as in dependant and independence.

Angiosperm: Two-part word from modern Latin Angiospermae, where angio- is from the Greek angeion meaning vessel, and sperma meaning seed, where angiosperm refers to flowering plants that have seeds encased in a fruit. The term was coined by Paul Hermann in 1690 who made the important distinction with gymnosperms that bear naked seed not encased in a flower (Bahadur et al. 2015, PDF)

Anion: From Greek anion meaning going up or towards, from ion meaning to go (cf. Cation meaning to go away from). The term is attributed to William Faraday in 1834 when he observed dissolved substances in aqueous solution moved from one electrode to another, one being negative, the other positive although Faraday did not know what it was that moved (the discovery of negatively charged ions was made by Phillip Lenard in the 1890s). Interestingly, it was a colleague William Whewell who actually suggested the names anion and cation in 1833.

Antarctic: Ant- or anti- meaning opposite, so Antarctic is opposite the Ursa Minor and Ursa Major constellations – see Arctic (from Greek Antarktikos) and Latin Antarcticus. May have been discovered by Polynesians many centuries ago, but the first European discoverers were in the 1820s. According to R Bulkeleyv (2015) the name was first applied in 1840 at a congress of Italian scientists, and the earliest map to show the name in 1843.

Anti- : From old Greek anti- meaning against, opposite, and later from Latin. As in anticline; antipathy. Also used in the sense of ‘before’ as in antipasto.

Anticline: From the Greek anti- meaning opposite, and -cline meaning a slope. In common use at least by 1840s but as the adjective anticlinal, to describe folded strata and ridge types in geomorphology. It reached a level of prominence in the 1840s and later in the anticlinal theory of oil and gas trapping. The noun form – anticline appears to have been derived from this a bit later and was in common use by 1860s-70s.

Apophysis: (noun). Plural apophyses. From two Greek word elements: the preposition apo meaning from or out of, and phuo meaning to bring or grow, giving apóphusis meaning offshoot, side-shoot, or spur. Used (infrequently) in geology to describe structures like small offshoots from igneous dykes or veins, or some crystal structures.

Aqua-: From Latin aqua meaning water, and akwa from PIE. As in aqueous, aquatic from Latin aquaticus.

Aqueous: From Latin aqua meaning water. Probably 17^th C – the French form aqueux (masc) and aqueuse (fem) was used by Antoine Lavoisier in his Elements of Chemistry 1789.

Arc: From Latin arcus and arcum to Old French arc with lineage in Old English (pre-1180 CE), German, Norse and Greek, meaning bow, curve, or curved line with reference to the motion of a celestial body (Sun, Moon, stars) across the sky. Middle English ark also referred to the segment of a circle.

Arctic: From Greek Arktos meaning bear, that may refer to the northern hemisphere constellation Ursa Major and Ursa Minor; it may also derive from Arktouros which is the Greek name for the star Polaris or Pole Star. Probably discovered initially by ancient Greeks or Vikings, although history tends to record the first European-North American discoveries by Frederick Cook and Robert Peary in 1909 (although even this record is debated). Notwithstanding the fact that Inuit lived in the region for centuries before Cook and Peary.

Arenite: (noun) From the Latin arena meaning sand, and the word element -ite originally from the Greek itis and ites, and later the Latin ita. I could not find use of the term in any of Lyell’s (1830s) or Geikie’s work (1888). F. Pettijohn (Sedimentary Rocks, New York, Harper & Bros, 1949) mentions arenite as a useful term, and notes an earlier use (and spelling) of arenyte by Amadeus Grabau (p.14). Grabau uses the term arenyte (as well as rudite, lutite) on several parts of his Principles of Stratigraphy (1913), as in “‘Thus a rudyte following an arenyte may well be considered a distinct stratum” (p.699). Grabau may have used the term in earlier publications. The adjective arenaceous derives from this word.

Arkose: In sandstone classifications an arkose contains 25% or more detrital feldspar. The word is probably French, where it was first used by Alexandre Brongniart between 1823 and 1826, and later borrowed by Roderick Murchison in 1839. I have not found Brongniart’s article, but the word does appear in volume 46 of the Dictionnaire des Sciences Naturelles, Tome XLVI in 1827, where Brongniart is listed as a contributor.

-ary: A word-forming element used as a suffix in words like sedimentary, dictionary to form nouns and adjectives. It derives from the Latin elements arius, aria, and arium, and appears in some Middle English writing – also Middle French -arie.

Ash: An old, and familiar word probably rooted in PIE, and later Proto-German askon to Old German aska, and Old English aesce (written as the digraph ae) or asce all meaning the products of fire, particularly dusty products. Interestingly, the Old English word for the tree elder-ash was ellenahse. There are multiple spellings in Middle English where either consonants ‘k’ or ‘h’ are inserted –  asche, aische, aske,  asken, axen, asshen, asskess, asshes. The Latin word cinis was used to describe the ash remain of a cremated person, as well as the products of fire and explosive volcanism. In a letter to Cornelius Tacitus, Pliny the Younger used cinis in his descriptions of Vesuvius eruption (79 CE) – as in the translated version (William Melmoth, “The ashes now began to fall upon us, though in no great quantity.” (Pliny’s full name was GAIUS PLINIUS CAECILIUS SECUNDUS). The Christian tradition Ash Wednesday marks the first day of lent; traditionally it involved placing ashes on a celebrant’s head. The word ash is also linked to dust, as in the sepulchral phrase “from dust to dust; ashes to ashes”. One of the earliest references to volcanic ash is in a brief note to the Royal Society Philosophical Transactions (Volume 1, January 1666) by Henry Robinson, concerning an eruption at Vesuvius “A Relation of the Raining of Ashes, in the Archipelago, upon the Eruption of Mount Vesuvius, some years ago.” In the letter Robinson notes “There was no Wind stirring, when these Ashes fell, it did not fall onely in the places, where we were, but likewise in other parts, as Ships were coming from St. John D’Acre to our Port; they being at that time a hundred Leagues from us. We compared the Ashes together, and found them both one. If you desire to see the Ashes, let me know.” (These quotes from the Gutenberg Library).

ASL: Common acronym for Above Sea Level, but also used for Absolute Sea Level, Average Sea Level, and American Sign Language. Use is post-19^th C when tide gauge measurements became a necessary part of oceanography.

Asteroid: The root aster is from the Greek aster meaning star, and asteroeides meaning star-like. The name was coined for bits of space rock by William Herschel in 1802 after much hand-wringing, and not wanting to have a name that had the context of planets or planetessimals. Herschel had even asked some of his astronomer colleagues, but in the end, he came up with the name we use today. Some have argued that the name was coined by Stephen Weston, an acquaintance of Herschel’s, but this seems to have been dismissed.

Asthenos- From Greek astheneia meaning weakness. Thus asthenosphere – the weak layer within the Earth’s sphere. Introduced to the literature by Joseph Barrell in 1914, with his publication of the composition and structure of the lithosphere – in the Journal of Geology, v. 22, part 7; The Strength of the Earth’s Crust: Part VI; Relations of isostatic movements to a sphere of weakness – the Asthenosphere. OA

Astro-: From Greek word element astro- meaning celestial body, and astron or astra meaning star. The word astronomy is also ancient Greek, adding the stem nomos meaning law, custom or precept. In western literature the word astronomy was generally applied to celestial body science from about the 17^th C. Prior to the 17thC astrology and astronomy were both used to express the same attributes of the stars and planets. Astrolabe dates back to pre-medieval times and refers to an astronomical instrument to chart the movement of stars and other heavenly bodies. In English astrolabe is commonly referred to as early as late 14^th C in Chaucer’s Canterbury Tales.

@: The symbol that defines modern digital communication is generally understood to have been developed by Medieval monk transcribers and merchants who devised it as a shortcut, possibly for the word ‘toward’. The earliest recorded use is 1536, by a merchant who documented costings “at the rate of…” with an @. Its introduction to modern communications was by computer scientist Ray Tomlinson in 1971. .

-ate: From Latin …atus and …atum meaning having or possessing the quality of something; used to form nouns, adjectives and verbs. Examples: sulphate (noun), as in having the quality of sulphur; approximate (used as an adjective and verb); coordinate (used as a verb and noun).

Atlantic: The name is derived from the Greek Atlantikos and Latin Atlanticus for Mount Atlas in Mauritania. The oldest known reference is from a 6^th C BCE Greek poem, where  Atlantyke designated the seas outboard of that location. European literary reference includes Rabelais’ Gargantua and Panteguel (1534) where he makes reference to the “Atlantic sea”.  Some of the 16^th C European maps refer to Oceanus Occidentalis (North Atlantic) and Oceanus Ethiopica (South Atlantic) with the latter used in some circles until the 17^th C. One of the oldest maps by Martin Waldseemüller (1513) shows the Americas separated from Europe-Africa by a large expanse of ocean, a concept that, up to that time, would have been controversial because it upset the general Ptolemaic belief that Europe-Africa were surrounded by ‘seas’. 

Atmosphere: From the Greek atmos meaning vapour and sphaira meaning sphere. The latinized version is atmosphaera. One of the earliest uses is 1638 in the Discovery of a World in the Moone by John Wilkins. His discourse refers to Atmo-sphæra three times, the last of which is proposition – “Prop. 10. That there is an Atmo-sphæra, or an orbe of grosse vaporous aire, immediately encompassing the body of the Moone.” Note the use of the diacritical æ that became more common in English words formed from Latin and Greek in the 16^th C.

Aurora: From Latin Aurora, the Roman goddess of dawn; the Greek equivalent is Eos, the first to awaken and announce the beginning the new day.

Aurora Australis: (Southern lights) From Latin Auster meaning the south wind. Apparently named by James Cook during his voyage in 1772–75 on the Resolution.

Aurora Borealis: From Boreas who is the Greek god of the north wind, and the Latin borealis based on the Greek name. Historically seems to have been named by French philosopher-astronomer Petrus Gassendus after he had witnessed an event in France on September 2, 1621. Gassendus also surmised that the source of the ‘northern lights’ was at high altitude.

Auto-: From Greek autos meaning self or same; as in autocyclic, autoimmune, automobile, autotroph.

Autochthon: From Greek autokhthon meaning from the soil or land, used in reference to natives of the land referring to plants or aborigines. The adjective form autochthonous probably dates to earliest 19^th C – the Merriam-Webster Dictionary cites 1805 in a periodical called Critical Review, where the author William Taylor makes reference to the English “…predilection for autochthonous bread and butter”. Usage increased dramatically from about the 1940s and particularly with the advent of continental drift and plate tectonics in the context of structural-tectonic components of Earth’s crust or lithosphere originating in place. Cf. allochthon and allochthonous.

Autogenic: from Greek autogenetos meaning self-born or self-producing. The word autogenic has been in use since the mid 19^th C. Early usage was in a medial context. More frequently read after James R. Beerbower’s 1964 paper where autocyclic and allocyclic are defined in a geological context.

Ballistic: (adj, noun) From the Greek verb ballein meaning to throw, evolving to the Roman Latin form ballista, that had several meanings, primarily as a siege machine for throwing large rocks, and as a javelin thrower. Da Vinci took the science of ballistics to a new level, particularly in the design of artillery- a giant crossbow and catapult for launching projectiles, and a mortar. Their design and use incorporated typical projectile parabolic trajectories, the science of which was advanced by da Vinci and Galileo. I have not found reference to volcanic ballistics prior to the 1940s – although there is frequent reference to volcanic bombs (e.g., Minakami, 1942).

Bar: Its sedimentological context is derived from the original meaning of barrier, that probably dates back to 12^th C Middle English (from old French barre meaning a gate or beam used to secure a gate. The meaning was extended to sand barriers that had to be negotiated by sailing vessels. The term is a root for the word sandbar in rivers and coastal settings in addition to sandbank – the latter was used by Leonardo DaVinci in his various studies of water i.n river channels and canals, late 15^th C and early 16^th C.

Baro-: From the Greek baros meaning weight. It was borrowed as an expression of the weight of the atmosphere, or pressure – hence barometer invented by Evangelista Torricelli (1608-1647), an Italian mathematician and physicist, who based the invention on his discovery that air pressure could support a 76 cm column of mercury (equivalent to a pressure of 1 atmosphere).  He also spent some time with Galileo. As in words like barocline, barograph

Basin: From Latin baccinum and 13^th C French bacin, originally meaning a dish or vessel that holds water. The geomorphological meaning associated with rivers, lakes and drainage basins dates to early 18^th C. Playfair’s 1802 precis of James Hutton (1785-88) makes no mention of the word basin. By 1830, Charles Lyell uses the term frequently as a geomorphic term and in reference to coal-basins. In modern geology it generally refers to sedimentary basins and fluvial drainage basins. One of the first sedimentary basin classification schemes was proposed by Marshall Kay, 1951 in his GSA Memoir chapter North American Geosynclines.  

Batho-: From ancient Greek bathus meaning deep. As in Batholith (a deep intrusive body), and bathyal (deep ocean.

Bathymetry: From the Greek bathus or bathos meaning deep, and the word element -metry from Greek – Latin metria meaning measure.

B.C. Literally, Before Christ, an expression probably first used by the Venerable Bede (a Christian monk) in 731. It has largely been replaced by B.C.E. (Before Common Era) that has no religious context.

B.C.E. Literally, Before Common Era. Historical dates quoted as BCE are the same as BC, that track history before A.D. or the C.E. BCE is regarded as a religiously neutral expression. It is not a modern expression – was used by some well-known writers during the Enlightenment (e.g. Isaac Newton).

Be that as it may: Idiomatic English of unknown origin. Some attribute it to Chaucer. The first part ‘be that…’ is frequently used by Chaucer in Canterbury Tales (1387 – 1400), as in “if so be that thou finde that,” which could be written as ‘if that be the case,”. Chaucer also uses the second part ‘as it may’ separately, as in “And dryve forth the world as it may be,” but I could not find where he might have put the two parts together.

Bed, bedding: The origin of bed in the context of a sea-bed, where things come to rest, is from 16^th C old English bedd. But the use of bed in the sense of a resting place or dug plot goes back to Indo-European roots. The geological context as in a stratum, is from late 17^th C although it may not have been used as frequently as strata and stratum. John Morton 1712, in his ‘Natural History of Northamptonshire’ wrote “Of the Freestone above the Ragg were four strata, Courses, or Beds, as they are sometimes called…”.  John Playfair’s (1802) precis of James Hutton’s opus makes frequent use of the terms bed and beds, but not bedding (I searched his text on the Biodiversity Heritage Library). William Smith’s regional geological maps (1819-1824) also contain references to Chalk and other beds.   Although Smith and Playfair use strata and stratum much more frequently. Charles Lyell makes frequent reference to beds (e.g. sandstone beds) and also to the bed of the sea in his Principles (1830-33), but not bedding. However, in his Manual of Elementary Geology, 1855, there are at least three references to bedding in his chapter on metamorphic rocks. A quick check of late 19^th C and early 20^th C publications indicates more frequent use of the word bedding, for example texts by J. Dana, A. W. Grabau, and J. Barrell. The idiomatic sense, as in “You’ve made your bed; now you must lie in it!” probably dates from 15^th C French.

Bi- A common prefix meaning two, or double. Of ancient use – from PIE dwi, and the English form from Latin bi-.

Bio-  From the Greek bios meaning ‘life’, used originally as one’s life (biography), but from the early 19^th C it also became a scientific term designating all life. As in biology, biofacies, biocoenose.

Bomb: The early Greek bombos and Latin bombus both were used to connote deep or booming sounds, perhaps like those emanating from a volcanic eruption or a landslide of rock. As an explosive device it originates from the 16^th C, probably coinciding with the introduction of gunpowder to western Europe – again the word connotes a deep sound. The volcanic context of bomb, as an eruption ballistic was used as early Lyell’s 1833 volume of the Principles – in his Glossary (p.82) “Volcanic Bombs. Volcanos throw out sometimes detached masses of melted lava, which, as they fall, assume rounded forms (like bomb-shells), and are often elongated into a pear shape.” Presumably, Lyell learned the term from some earlier document or discussion.

Bouguer gravity anomaly: Named after Pierre Bouguer (1698 – 1758) who was one of the first to measure the gravitational deflection caused by topography (in Ecuador), and who recognised that the measured deflection was less than the value he had calculated. He had no explanation at that time – this was later explained by Airy and Pratt (isostasy models) who hypothesized a mass deficiency beneath the surface (datum).

Boulder: Of Scandinavian origin from bullersten where the root bullra means load or roaring, and sten means large stone, and the Proto-German word element bul. The Middle English version bulder ston meaning cobblestone is based on these word elements. The spelling bowlder is archaic – the example I note is from Mignon Talbot’s 1911 paper on the discovery of the dinosaur Podokesaurus holyokensis. One of the earliest uses of the modern geological context is John Playfair’s Illustrations of the Huttonian Theory of the Earth where he refers to “The Boulder-ftone of Borrowdale…” (1802, p. 398).

Bouma cycle: The characteristic, ideal sequence of lithologies and sedimentary structures commonly observed in turbidites; first published by Arnold Bouma in 1962 and named after him (Sedimentology of Some Flysch Deposits. Elsevier Publishing Company).

Bowlder: An old spelling of Boulder.

() Brackets, parentheses: The four main types of bracket are chevrons ❮❯, rounded ( ), squares [ ], and braces { }, introduced at different times for different tasks. The earliest were the chevrons. ( ) were introduced to western writing by Erasmus of Rotterdam (Desiderius Erasmus Roterodamus – 1466-1535), an influential theologian, philosopher, and prolific writer (Latin). Erasmus referred to these as lunula after the Latin luna for crescent moon. The other two forms appear with typewriters and computer codes. The word parentheses (singular parenthesis) is more commonly used in American English, brackets in British English although parentheses is also used. (Wikipedia).

Calcium: From Latin calx meaning lime or limestone, and Latin suffix –ium. Discovered and named by Sir Humphry Davy (1778-1829), first isolated in 1808 by electrolysis of lime.

Calculus: From Latin calculus meaning to reckon or count. Although Isaac Newton and Gottfried Leibniz are both credited with its invention in the mid- to late 17^th C, it seems that Leibniz was the first to coin the name.

Carbon: The 6^th element in the periodic table (atomic number 6), named charbon by French chemist Antoine Lavoisier in 1787. The name is from Latin carbonem meaning coal or glowing coal. Lavoisier discusses the reaction of coal in oxygen in Traité élémentaire de Chimie, (Elements of Chemistry, 1879), Chapter 5 “De la décomposition du gaz oxygène par le soufre, le phosphore & le charbon, & de la formation des acides en général.” “On the decomposition of oxygen gas by sulfur, phosphorus and carbon, and on the formation of acids in general.” Lavoisier also named the element oxygen.

Carbonate: (noun) From the late 18^th C chemist Lavoisier ‘salt of carbonic acid’, from Latin carbo meaning ‘a glowing coal’, adapted by Lavoisier who named the element carbon. Also used as a verb – to carbonate – adding carbon dioxide to form carbonic acid.

Cation: From Greek cation meaning going down or away from, from ion meaning to go (cf. Anion meaning to go towards). The term is attributed to Michael Faraday in 1834 when he observed dissolved substances in aqueous solution moved from one electrode to another, one being negative, the other positive although Faraday did not know what it was that moved (the discovery of negatively charged ions was made by Phillip Lenard in the 1890s). Faraday’s colleague William Whewell actually suggested the names anion and cation in 1833.

C.E. Literally, Common Era. It replaces A.D. but is exactly the same number of years or dates. The phrase Common Era was commonly used during the enlightenment and later.

Celsius: The temperature scale based on values of 0^o C for water freezing and 100^o C for boiling, devised by Swedish physicist Anders Celsius in 1742. He originally called it centigrade from the Latin centum meaning 100, and gradus meaning step-wise. The scale name was later changed to Celsius by the International Committee for Weights and Measures in 1948 in his honour.

Cell: From Medieval Latin cela and celare meaning a small room (from which we also get cellar) – one of the earliest usages as monastical rooms for monks. Earliest use in English is probably Robert Hooke in his Micrographia (1665) where he outlines the use of microscopes and describes the objects he observed (the point of a needle, cloth, spiders). His use of Cell was for small chambers or bubble-like structures observed in corks and some spiders. A copy of the original text is available on the Biodiversity Heritage Library.

Ceno-  From ancient Greek keinos, that in English means new or recent. As in Cenozoic – the most recent geological era.

-cene: As a word-element (suffix) it has the same meaning in Greek as the prefix, but is used to define more recent in successively younger stratigraphic Systems, such as Pleistocene, Pliocene, Miocene etc. All of these systems were originally established to indicate the more ‘modern era’ following the Mesozoic and much older Paleozoic.

Certain: From Vulgar Latin certanus and classical Latin certus meaning reliable, invariable, fixed. Thence Old French (12^th C) certain, cert, of the same root as Spanish cierto and Italian certo. The modern meaning is the same.

cf.  From Latin confer meaning compare. Commonly used to provide alternative ideas, texts, statements, publications.

Chaos: (as in Chaos Theory). From Greek khaos meaning void, empty and later meaning disorder; also later Latin chaos. Used in symbolism and metaphor in Renaissance painting, such as Titian’s Presentation of the Virgin to the Temple (1534-38). Also in Da Vinco’s writings. The antithesis of harmony, order out of chaos in an early representation of self-organizing of existence and the universe. In physis, chaos theory maintains that underlying any apparent randomness there are deterministic patterns that can be elucidated.

Chrono- A word element as both prefix and suffix. From ancient Greek khronos, meaning time, and Latinized to chron-. Examples: chronostratigraphy, chronology, diachronous.

Chronostratigraphy: The study and deciphering of time relationships of rocks and strata. Formally introduced in 1881 at the Second International Geological Congress in Bologna, Italy, where its definition and guidelines-rules for implementation were codified. See paper by G.B. Vai, 2007.

Circa: Also abbreviated as ca.  From Latin, meaning approximately or about the same value, frequently used with dates.

Classify: (verb) From the Latin classis meaning class or division, thence French classe and classifier meaning to order or arrange as classes, groups. Hence French and English classification (noun). The earliest use I’ve found is Da Vinci (1452 – 1519) in the translated version of Atmosphere. Used frequently by Francis (Lord) Bacon (1620), as in “The classification of human reason and animal instinct”, and the chemist Lavoisier (1789) with reference to “une classification méthodique”.

Clast: (noun)- clastic (adj.) From the Greek adjective klastos (clastic) and Latinized to clast, meaning broken, pieces. I have not found any reference to clast or clastic in Hutton (1795), Playfair (1802) or Lyell (1830 and later) publications. One of the earliest uses I could find was Archibald Geikie (1882) who refers to “Clastic, fragments, composed of detritus” (p. 87) in Text-book of Geology.   Joseph Barrell (1910) refers to “clastic sediments” in his Geology of Connecticut, and again in 1917 in his iconic Rhythms and Measurements paper.

Clay: Probably of PIE origin, linked to Proto-German klaijaz and Old English clæg meaning sticky, or stiff, or the adjective form clǣig meaning clayey. The Middle English equivalent is clei and cley which is close to the modern spelling. The figurative sense as in ‘feet of clay’ is Old Testament biblical. Cognates include the Latin gluten meaning glue, hence gley as in a sticky clay soil, and ancient Greek gloios meaning something sticky. James Hutton (1795) makes frequent use of clay as an Earth material. The term Clay was used to name stratigraphic units such as the London Clay and Kimmeridge Clay from early 19^th C, including William Smith’s iconic geological map published 1815. Clay has the distinction of being both a mineral name (clay group of minerals), and a grain size for particles 0.004 mm (4 microns) and less.

Cleavage: From Old English cleofan meaning to split apart, and Proto German kleuban which gives us the root cleave (verb). The noun cleavage is probably early 19^th C to describe penetrative fabrics in deformed rocks. Lyell (1830-37) in the ‘Principles’ mentions this context on several occasions. Henry Clifton Sorby’s On the Origin of slaty cleavage, published in the New Philosophical Journal (Edinburgh) in 1853; John Herschel wrote a paper on this topic in 1856 (On slaty cleavage, and the contorsions of rocks, Philosophical Magazine. vol.12, pp. 197-198). The OED has the earliest usage at 1816.

-cline: As a suffix, connoting slope, lean, or fold, from the Old English 13^th C verb clinen or old French cliner meaning to bend. Examples: incline (a slope), anticline–syncline (folded strata). It is used as a verb as in ‘disposed toward’. Thus, ‘I am inclined to walk that incline’.

Clino-: A word-forming element (prefix) derived from the Greek klinein and later Latin clin or clino, meaning to lean or slant – also incline. Examples: clinoform (dipping strata), clinopyroxene probably associated with inclined extinction in thin section under polarized light.

Coarse: (adj) Possibly evolved from the Middle English noun cors and cours course meaning track or path, although the change in meaning of coarse to vulgar, lack of elegance, or roughness is not known. The context of coarseness, lumpiness, or roughness, as opposed to fine or smooth was in common use by the 15^th  C – commonly used to describe cloth.

Cobble: (noun) Probably derived from Old German and Old English cob meaning lump, head (of something – hence corn cob) or heap, and Middle English cop or coppe meaning head. As a rounded stone, as in cobblestone – the OED notes earliest use about 1440. The verb to cobble (together) is probably 16^th C. As a defined grain size look to Udden (1914) and Wentworth (1922). The word cobbler (mender of shoes) may have had a similar root – cob; Rabelais used it in the sense of “The Cobbled Shoe of Humility” in Chapter 2, part VII of Gargantua and Pantegruel (1532 ~ 1564).

Colour – color: From the Old Latin colos thence classical Latin color meaning hue or appearance is closest to the common American spelling color dating from the 15^th C. Old French took the Latin color, but this morphed to modern French couleur. Old English (Anglo-Saxon) had a word for hue – hiw. The English spelling colour dropped the first ‘u’ (from the French) and seems to have been common from the 14^th C, as in Chaucer’s Canterbury Tales (1392), also in James Hutton’s Theory of the Earth (1795). Francis Bacon’s Novum Organum (1620) on the other hand uses color spelling. The American spelling color is closest to the original Latin. A person showing their true colours has its origin in coats of arms and insignia from about 14^th C.

Column/Columnar: From the Latin columna meaning pillar, as in architectural design, from columen meaning top of or summit – this last form has clear PIE roots as in kel. Thence Old French colombe and Old English columne. The modern noun entered late Middle English in the mid-1400s primarily as an architectural term. Georgius Agricola illustrates such columns in his De Re Metallica (1556).   The adjective form columnar derives from the Latin root. James Hutton (1795) used column to describe lava derived from great depths, rising to heights as it builds an edifice – an eruption of Etna is the example quoted. He also observes large rocks tossed from the summit during an eruption (ballistics, bombs). “A stream of melted lava flows from the sides of Mount Aetna. Here is a column of weighty matter raised from a great depth below, to an immense height above, the level of the sea, and rocks of an enormous size are projected from its orifice some miles into the air.”. The volcanological term eruption column is not explicitly stated, but perhaps implies. Joints in lava flows, like those in the Giants Causeway (well known in the 17^th and 18^th C) were also described as columns – one of the first accounts is in a letter from Richard Bulkeley to Martin Lister in 1693, published in the Royal Society Transactions. The modern term is columnar joint.

Comet: From Greek kome meaning hair and kometes meaning long haired, thence Latin and Old English cometa. Sightings of comets go back more than 2000 years. Halley’s comet is probably the best known, in part because it appeared before the Battle of Hastings in 1066 and was later added to the Bayeux Tapestry completed in 1077 showing people looking up to and pointing, with the words Isti Mirant Stella embroidered. Edmund Halley (1656 to 1742) introduced the scientific concept where comets like the planets orbited the Sun. He calculated Halley’s comet periodicity at 76 years, which is pretty close to more recent calculations (75 years). Mark Twain revelled in the knowledge that he was born under Halley’s comet in 1835.

Comma (,): Next to the period/full-stop it is the most used mark of punctuation. It is derived originally from the diagonal slash (/) that first appeared in the 13^th century and represents a pause in writing or reading. Its Latin name was virgula suspensiva. In the 15^th century a replacement mark was introduced by an Italian printer Aldus Manutius. The word comma is from the Greek koptein, meaning “to cut off.”

Compass: From the Latin compassare to the Old French verb compasser meaning to measure, and the noun form compass meaning circle, divide. The pair of compasses as an instrument for geometric measuring and construction and was probably used in ancient Greece. Galileo constructed several proportional compasses for these purposes.  The magnetic compass was used in China almost 2000 years ago for religious purposes, later became the primary instrument to find direction – to orient. The earliest records of use in Europe and Islam are 1190 CE. Early compasses consisted of a magnetized needle in a bowl of water. The more familiar navigation compass is from the 14^th-15^th C. See Kreutz, Barbara M. (1973). “Mediterranean Contributions to the Medieval Mariner’s Compass”. Technology and Culture. 14 (3): 367–383.

Con-: Also com-. A Latin word element meaning together. As in conformity, conjunction.

Confine: (verb) From the Latin word element con- meaning together, and finis meaning limit or end to confinis and confinare. See also the etymology of fine. To Middle French confins.

Conformity-conformable:    From 14^th C French conformité, then 15^th C English, particularly in context of adherence to church doctrine. The adjective conformable was used many times by James Hutton (1785) and Playfair (1802) in the context of conforming to some principle, hypothesis, fact, or analogy, but not, it seems to stratigraphic succession relationships. However, Charles Lyell in his Principles, and Manual of Geology frequently does use conformable in a stratigraphic sense, but conformity far less often and always in the sense of conforming to, as per Hutton’s usage.

Conglomerate: From two Latin roots, con- meaning together, and glomus and glomer meaning ball, thence Latin verb conglomerare meaning to roll, cluster, or gather together, the past participle conglomeratus, to the Middle English noun and adjective conglomerate – a gathered mass of rounded objects. The OED places the earliest use as a verb in 1572. Its use as an adjective and noun probably precedes Newton’s Latin version conglomerata in his Principia (1686). James Hutton (theory of the Earth, 1795) as far as I can tell only used the term puddingstone, although he quotes a French title “Brèche Puddinstone Conglomérations”. Lyell in his Principles (1830-1833) used both puddingstone and conglomerate as a rock description. Its more formal inclusion as a sedimentary descriptor was from Wentworth’s (1922) grain size paper (Journal of Geology, OA)

Crater: From the Greek krater, thence Latin crater meaning a mixing bowl. Lunar craters were first discovered by Galileo who made sketches of several, but it is not clear whether he used the word crater. Robert Hooke in 1665 proposed possible origins for the bowl-shaped structures including volcanic eruptions, but discarded the possibility of meteorite origins (Hooke, Micrographia; Royal Society).  G. K. Gilbert in 1892 was the first to suggest lunar craters were formed by impacts.

Crust: From 13^th C or 14^th C the hardened outer layer of bread (French crouste). Also, as a pie crust that in 16^th C was known as the coffin or coffyn. Isaac Newton (late 17^th C) hypothesized that Earth had an outer layer and a denser inner layer, and in 1692 Edmund Halley proposed a “Hollow Earth” around an outer shell – I’m not sure whether Newton or Halley used the term crust, but they certainly gave impetus to the idea of Earth’s outer layer.

Current: In the context of flowing, from Latin currere meaning to run, to Old French corant (running or swift) and Middle English (1066 – 1450) noun and adjective current – the latter context relates to flowing water, as in tides. Current in the context of present or at this time is probably 15^th-16^th C; hence concurrent. Robert Hooke (1665) uses current in the sense of motion (of small bodies – p. 212, p. 232), and concurrent in the context of timing (p. 27, p. 123) in his Micrographia. Counter-current also used as early as 1620 with Francis Bacon’s Novum Organum in relation to fluid flow.

Cycle:  From ancient Greek kyklos meaning circle, or recurring motion in a circle, returning to the starting point, and later Latin cyclus. One of the earliest uses (2^nd and 3^rd centuries BCE) is with epicycles, or circles within circles, from Greek epíkuklos, to describe astronomical motions (e.g., Ptolemy), in particular the motions of planets (wandering stars). Leonardo da Vinci (15^th C) wrote a great deal about the science of water-cycles, and later Nicholas Steno (17^th C) about cycles of sedimentation, but it seems that neither used the Latin word ‘cyclus’ or its derivatives. James Hutton, quoted in Playfair (1802) employs the word in the sense of a “great geological cycle”. Use of the word expanded in 18^th and 19^th centuries to include hydrological, geological, and geochemical cycles.

Darcy’s Law: Named after Henri Darcy who, in 1856 published an empirical relationship between hydraulic gradient and discharge for groundwater flow through a porous medium. The experimentally determined relationship is: Q = -KA(Δh/D) where

• Q is discharge,
• K is a proportionality constant, subsequently called the hydraulic conductivity
• A is the cross-section area of a flow tube (Q is also proportional to A), and

Δh/D the head difference between two locations along a flow path, at distance D.

Darcy velocity: Named after Henri Darcy where the proportionality constant K in the statement of his Law, has dimensions of L/T, that mathematically is equivalent to velocity.

Data: From Latin meaning something given, it is the plural noun of datum. It is generally accepted that it can be used with both plural and singular verbs, thus the data is…, and the data are… NB. The use of datum as singular is rare these days, except as a technical term for a point or reference, a bit like the words agenda and information, both of which are now accepted as either singular or plural (except by grammar pedants).

Datum: Is the Latin singular of data, meaning something given, or a basis for measurement and inference; for example, the basis for an argument. A datum as a point from which measurements can be taken, was used by ancient Greece, and probably early China. Its more modern scientific use is in geodetics, as an invariant reference point or surface for measurement of elevation, such as sea level, or a starting point from which time is measured. The first National datums were the North American Datum (NAD – Horizontal and vertical) in 1927.

De- A common word element in English, primarily from Latin de- meaning down, down from, off. As in Deposit (laid down); describe (lay down in writing); deflate (to let down).

Decimal: From the Latin decem meaning ten, and decimus meaning tenth. Although the ancient Greeks, Indians and other used numeric systems based on values of ten. However, the invention of the decimal point is often credited to a German mathematician Christopher Clavius in 1593 who used it in a table of sine values, but it seems he borrowed it from Italian mathematician Giovanni Bianchini in the 1440s, who used it in spherical astronomy and meteorology calculations; it changed the way we represent fractional numbers (van Brummelen, 2024).

Degree: From Old French degré and possibly Latin degrades to Middle English degree meaning a step, a stage, or steps in rank or hierarchy as in status. As an angular measurement it is 14^th C although the original subdivision of a circle into 360 equal steps, or degrees of arc dates to Sumerian (ca.5500 – ca. 1800 BCE) and Babylonian (1890 BCE–539 BCE) times, possibly associated with the Sun’s position. Babylonian counting was founded on a base 60, hence the division of degrees into 60 minutes and 60 seconds; 360 is evenly divided by 60.

 ° Degree sign: Although Claudius Ptolemy (~ 85- ~165 CE) used notation for angular degrees, minutes, and seconds, probably originating in older Greek astronomical measurements, historians consider them to be unlike the modern symbols. The earliest usage of the small ‘o’ at top right of a number is in the writings of Gemma Frisius (1508-1555) in a 1569 edition of Arithmeticae practicae moethodus facilis (in St.Andrews Math History). It was used by astronomers like Johannes Kepler. First use of the symbol to designate temperature was probably Henry Cavendish – in his Three Papers containing Experiments on factitious Air by the Hon. Henry Cavendish, F. R. S. 1766. He uses the degree sign without explanation, so it may predate this period. Antoine Lavoiser uses the notation to indicate primary (1^o), secondary (2^o) etc. in his 1789 TRAITÉ ELÉMENTAIRE DE CHIMIE, as in “Nous avons eu à considérer dans les corps qui forment cette classe, tels que les sels neutres, par exemple, 1^o. le principe acidifiant qui est commun à tous;” (We have had to consider in the bodies which form this class, such as neutral salts, for example, 1^o. the acidifying principle which is common to all:”)

Delta: From the ancient Greek delta, borrowed from Phoenician daleth meaning tent door. It is the fourth letter in the Greek alphabet. The Greek symbol is an open triangle – upper case Δ, lower case δ; the Latin versions are D and d respectively. The Greek philosopher Herodotus (about 490-420 BCE) is credited with being the first to use the word to describe the triangular shape of Nile delta – a usage that has persisted to the present. Isaac Newton made frequent use of the mathematical symbol δ in his Principia Mathematica (1687). I can find only two instances where John Playfair’s 1802 rendering of James Hutton’s Theory of the Earth (1795) uses the word delta in a more or less modern sense (Playfair, pages 429, 430).  

Density: From Latin densitas meaning thickness, and densus meaning dense or thick, thence to Old French dempsité and Middle French densité. Probably first described by Aristotle (384-322 BCE) in his Meteorologica where he compares the response of vessels floating in fresh water and sea water, and later defined by Archimedes (c. 287 – c. 212 BCE) to explain the displacement of bodies floating in water. Apparently Galileo tried to recreate Archimedes experiments. The context of matter (mass) in a certain volume is found in Galileo’s (1564-1642) Discourse concerning the Natation of Bodies Upon, and Submersion in, The Water, as “more dense”, such as “… that the fresh water is more dense, and the salt more tenuous and subtle,…” (Translated version 1663).

Deposit: From the Latin depositus, meaning to lay down or aside. An important early usage in the context of things laid down is in Francis Bacon’s Novum Organum, or True Suggestions for the Interpretation of Nature (1620), where he refers to bottle of wine laid down in a well, bodies in a cemetery. James Hutton in 1795 makes frequent reference to deposits at the bottom of the sea, pore spaces in rocks, and deposited from solution in rock and wood pore spaces.

Determine: (v) From the Latin determinare meaning to set limits or bounds, also from Latin terminus meaning end or limit, later Old French determiner. The OED suggests 14^th – 15^th C. As a solution to a problem, Newton in his Principa (1686) used the noun form determinationem and determination, as in “In hunc modum inveniri posset & quantitas & determinatio motus hujus circularis in vacuo quovis immense,” – “In this way, the quantity and determination of this circular motion in any immense vacuum could be found”.

Determinism: From the root verb determine and noun determination. The philosophical idea that there is only one possible outcome for any event. Originally elaborated by Greek philosophers (6^th-7^th C BCE), and later the Aristotelian school and the Stoics. It became an important part of Christian theological doctrine viz. the nature of God and whether God knows beforehand any and everything that has or will happen. The concept of determinism is central to mathematical functions in science and the development of models and stands in contrast to stochastic randomness.

Detrital/detritus: (adj./noun) From the Latin de- meaning away, and terere meaning to wear (as in abrasion) that combine to form detere and the Latin noun detritus. The geological meaning as loose sedimentary material (of any size and composition) is at least as old as James Hutton (1795), as in “…those stratified bodies, as having been formed of the materials that are natural to this earth, viz. the detritus of former bodies;” – Hutton used detritus, but not detrital. Charles Lyell also used detritus but not detrital in the first edition of his Principles (1830-1833).

Di-: From Greek and Latin, meaning two or double. It is used to create compound nouns and adjectives like dimorphous, diatomic. Not to be conflated with dia-.

Dia-: A Greek word element meaning through or between. As in diachronous (through time), diameter (through a circle). Not to be conflated with di-.

Diachronous: Originally from the Greek dia- meaning through, and khronos meaning time. The geological context was used very little before the beginning of the 20^th C.

Diamict: (adj) A combination of two Greek word elements, miktos meaning mixed or mingled, and dia- meaning through. The term was coined by Richard Flint (Flint et al., 1960) for rocks that consist of a range of clast sizes, from mud to boulder, and generally lacking any preferred fabric (with reference to Walter Wahl’s 1952 definitions of polymict and monomict). It is principally (but not always) applied to deposits of glacial origin (e.g., glacial moraines).  The deposit, or rock name is diamictite.

Dimension: As a measurable quantity like mass, length, time, from the Latin dimensionem, probably 14^th C – this is the context used by Francis Bacon in his Novum Organum (1620). As a more figurative notion of some other universe or realm, probably early 20^th C. H.G. Wells also used the Fourth Dimension in his 1895 The Time Machine. The context of dimension as something measurable dates back at least to Greek philosophers like Aristotle (384-322 BCE) who treated a line as having “magnitude in one way, the plane in two ways, and the solid in three ways,” although the actual word was not used (Henry Manning, 1914; Internet Archive)

Dinosaur: From ancient Greek deinós meaning terrible, awesome, and also ancient Greek sauros meaning lizard (Latinised to saurus). The word was coined in 1804 by Sir Richard Owen, a well-known British paleontologist and anatomist, a contemporary and serious critic of Charles Darwin’s evolution theory. He was also a contemporary of Henry De la Beche and Mary Anning. A short piece on Owen written by Ferwen is well worth reading.

Direction: From the Latin directionem, from the verb regere meaning to guide or give direction to. The Middle English verb dressen is also derived from the Latin dirictiare, meaning to make direct or straight, prepare, and reach. However, the modern form is probably a direct derivation of the Old French direccion and later the Middle English direccioun.

Dis-: In modern English it derives from the Latin word element dis- and Old French des- meaning opposite to, not, apart (from), as in disallow, disproportionate, disturb, but it has much older Proto-Indo-European roots.

Discordance: (noun) From the Latin verb discordare meaning to differ or quarrel, to Old French discorder, with the Latin word element -ance creating the noun, and meaning disagreement or differing opinions. Charles Lyell in the 1831 Principles used discordance in a conceptual context, as in modern causes not being the same as ancient causes, or a discordance of opinion; likewise Joseph Barrell (1917) used it to describe data sets that were not in agreement. Its stratigraphic sense, as in discordant (adjective) strata, or strata bound by a discordance was used by Geikie (1882) in his Text-book of Geology, and later by Elliot Blackwelder (1909).

Distance: Probably from Old French distaunce (early 14^th C) meaning strife or dispute (in this case the dis- word element meaning apart from), later morphing into Latin distantia meaning standing apart and leading to more modern meanings of separation of one point to the next by some length, near or far. Shakespear (mid to late 16^th C) used the word to convey emotion, and physical separation as in ‘far away’, described by sight and sound; “So far be distant; and good night, sweet friend. Thy love ne’er alter till thy sweet life end!” (Hermia, Act 2, Scene 2, Midsummers Night Dream).

÷: Division symbol: This is one of several symbols to indicate the division operator. It was introduced by a Swiss mathematician Johann Heinrich Rahn in 1659 and became the accepted symbol in Britain and the USA. It replaced the horizontal and oblique bars that signify fractions (although these symbols are still in use). The letters D and M were also used to signify division and multiplication. The earliest known record of the mathematical operation of division is the Indian Bakhshilli (or Bakhshali) manuscript (3^rd or 4^th C) adopted by Arab mathematicians, and eventually reaching Europe where Leonardo of Pisa, aka Fibonacci, adapted many of the principles (13th C). The symbol ‘:’ was also introduced by Gottfried Leibniz to indicate division.

Early: (adv) From the Old English ærlice meaning soon, near the beginning, from ær (adv) meaning before, soon. Ær is also a word element in Old English, such as ǣrdæg (early day), and ǣrboren meaning early or first born. Although the terms early and late as references to geological time were used informally in 19^th C, the formal definition of Early as part of a geochronological unit such as the Jurassic Period was 20^th C.

Earth: From Old Saxon ertha and Old English (pre 12^th C) eorde, meaning ground, soil; it also has PIE root in er. Its use as a planetary name derives from about the 14^th C – Earth is the only planet name not based on Greek and Roman mythology. Earth is usually capitalized when used as a proper noun, and non-capitalized when in the context of dirt, committing the dead to the ground, or as hyperbole as in ‘what on earth?’. As a word element in earthquake.

Earthquake: Compound noun from Earth (see above), Proto-German kwakōną and Old English cwacian meaning shake, quiver, or tremble. The spelling quake is Middle English (e.g., Chaucers Canterbury Tales, 1387 and 1400).  Earliest know use of the compound is also Middle English , or as erdquake. Also from Latin terrae motus – the Latin for earth, and motus meaning to move. From this to Middle English and Old French terremote.

Ebb: (noun and verb) Probably originally Old German, similar to ebbe and ebben, from the Medieval name Erbo meaning descendant or heir, thence Old English ebba, used figuratively to note the passage of time or decay. Galileo used (translated) ebbing in the context of lowering water levels in his Discourse concerning the Natation of Bodies Upon, and Submersion in, The Water, as “…that the abasement or ebbing of the water…”, (Translated version 1663). In 1665 the Royal Society issued instructions to mariners in its Philosophical Transactions “To remark carefully the Ebbings and Flowings of the Sea, in as many places as they can, together with all the Accidents, Ordinary and Extraordinary, of the Tides; as, their precise time of Ebbing and Flowing in Rivers,…”. Isaac Newton used this (and other) data sources in his explanation of ocean tides in his theory of universal gravitation in Book 3 of the Principia (1687).

Eccentric: From Greek ek meaning out of, and kentron meaning centre, to Medieval Latin eccentricus and late Middle English eccentric where it referred to geometric and astronomical orbits that were off-centre, particularly the planets. One of the earliest appearances is in a mathematics text by Robert Recorde (~1512-1558) (printed 1551). Recorde was also responsible for introducing the equal sign (=) to English mathematics. Later the word eccentricity was used by Milutin Milankovitch (1879 – 1958) to describe the mathematical orbit of Earth in relation to solar insolation – the eponymous Milankovitch Cycles.

Ecliptic: Has a similar derivation as the word eclipse, from Greek ekleipein and ekleiptikos meaning failure to appear. Also from Latin. In this case ecliptic is the plane containing (approximately) the Sun, Earth, and planets, such that a solar eclipse occurs when the Moon crosses this plane – a relationship recognized by Greek astronomers.

Ecology: Ernst Haeckel (1834-1919), the artist-zoologist who created so many wonderfully detailed drawings of living and fossil organisms, coined the term “Oecologie” in 1866 in his book Generelle Morphologie der Organismen. From the Greek oikos meaning house, dwelling place, or family) and logos meaning language, of knowledge, the study of things. The anglicised version ecology means the study of all those characteristics (biological, physical, chemical) that life forms depend on (extinct and extant). Hence ecosystem.

Ecosystem: A later variation on the word ecology, coined by British ecologist A.G. Tansley in 1935. The definition stresses the interdependency of all those physical environmental processes and biological communities.

e.g.: From the Latin exempli grati meaning for example. It is commonly used to introduce one or more examples of something. It can be used within or at the end of a sentence (e.g. it can also be used in parentheses). There are periods after the ‘e’ and ‘g’.

-ence: See -ance.

Endo-: Word element (prefix) from the Greek endon meaning within or in. e.g., endoskeleton – an internal skeleton. Cf. exoskeleton.

Eon: From Latin aeon and Greek aiōn, meaning age or period. In the Bible it apparently occurs 199 times as eon and eonian, that in the King James version of the New Testament were translated as age, world, eternal, everlasting and other appropriate synonyms. British geologists from Hutton to Lyell seemed not to use this term, even loosely or informally. It is now reserved for two major periods of geological time – the Phanerozoic and Precambrian Eons. The spelling eon is a simplification of the digraph ae in aeon.

Epi-: A common prefix, from the Greek epi meaning close, near, upon; a root word element in PIE and Sanskrit. Hence epifauna, epiphyte, epilogue, epicycle, epidemiology, epistemology.

Epoch: Early 17^th C from Latin epocha, meaning a point in time, or the beginning of a period of time. James Hutton (1785) used the Latin word epocha to describe a geological time. The anglicized version was in common use by early 19^th C to designate a geological period as in the Tertiary and Secondary (Mesozoic) epochs. The term morphed to a higher chronological order by the end of the 19^th C, to denote subdivisions within Periods, such as Lower Silurian. This usage continues today.

Equ-: From Latin aequi- as a prefix or element, meaning equal, even. Before a vowel, as in equal, equality, or equi… before a consonant as in equidistant, equilibrium

= (Equal): One of the best-known notations in mathematics, it was probably invented in 1543 by Robert Recorde, and English writer, who became tired of repeating the phrase “…is equalle to:” and decided to represent it using two parallel, straight lines that he considered to be visually equal.

Equal: (adj.) From the Latin aequalis meaning identical, uniform, and aequus meaning level, kind, equitable, or even. The Old French egal is a well-known word element in the French motto Liberté, égalité, fraternité, and the English egalitarian. The Middle English of Chaucer (Canterbury Tales, 1387-1400) uses equal and derivatives inequal, and the adverb equally, but also used the Old French word efen and egalite for equal and equality, in addition to the adjective euen, and verb euenen (to make equal). The equal sign (=) was introduced to English mathematics in 1543 by Robert Recorde. https://

Equator: From Latin aequare meaning to make equal, and the Latin phrase circulus aequator diei et noctis meaning a circle equalizing day and night in the context of a celestial line (14^th C). Later defined as a great circle equidistant from the North and South poles.

Equilibrium: From 17^th C Latin equi- meaning equal, and libra meaning balance or scale. Claude Louis Berthollet was one of the earliest exponents of chemical equilibrium in late 17^th – early 18^th C. The fundamental condition that systems move towards equilibrium when disturbed was proposed by Henry-Louis Le Châtelier in 1854.

Equinox: From medieval Latin equinoxium meaning equal day and night, later Latin aequinoctium (aequinoctii plural), from aequus meaning equal, and 12^th C French equinoce.

Era: From Latin aera, meaning – from which time is measured or calculated, or historical period, probably 16^th C or 17^th C, but may have had its beginnings in antiquity with reference to historical periods such as Byzantine Era. Early 19^th C British geologists tended to use ‘era’ informally (non-capitalized) to refer to any period of time, such as Pliocene and Recent eras, albeit at a higher chronological order within epochs (e.g., Lyell, 1837, Principles of Geology). By early 20^th C Era was used formally, as in Devonian Era (e.g., James Dana, 1880, 1905). Today, Era is reserved for Cenozoic (Tertiary), Mesozoic (Secondary), and Paleozoic (Primary), all former epochs.  

Erode: From Latin erodere and erosionem meaning to eat or gnaw away (hence rodent), then to Old French érosion, and English erode. Probably 15^th or 16^th C. Also applied to the human condition, as in the erosion of moral boundaries. Erode-erosion used by Lyell, Darwin, Dana, and other 19^th C scientists, but not as far as I can see by James Hutton (1795) who instead uses phrases like “wearing away”, or Nicholas Steno (17^th C). Usage bourgeoned during the 20^th C. Erosion as a process has become a foundational theme in Earth sciences – sedimentation, uplift and denudation, allowing us to glimpse the deep crust, and witness past and present sedimentation.

Eruption: From Latin eruptionem and eruptus meaning to break out, thence Old French éruption (14^th C). One of the earliest uses in English is in Rycharde Eden’s (Richard) translation of The decades of the newe worlde or west India, a text by Pietro Martire d’ Anghiera that was translated by Eden from Latin in 1555. Here, the word is used in the context of erupting springs, and “the evaporations of fyre”.

Et al.  From Latin et alii meaning to include other people, or other names. In science it is commonly used when citing a multi-author publication. There is no period after et but a period is added after the al. Example: N. Chamberlin et al. 1939. Address to parliament.

Etc. Middle English (15^th -16^th C) abbreviation from Latin et cetera, meaning ‘and so on and so forth’, or ‘and the others’ as in a list. Many publications prior to the 20^th C also used the abbreviation &c. As in “The outcrop contained bedforms such as trough and tabular crossbeds etc.”(Of course, the etc. in this statement would be frowned upon if it was written in a technical report or exam answer). There is always a period after etc.

Evidence: (noun) From the Latin root evidens meaning obvious, to Latin evidentia meaning proof. Thence Old French evidence, to Middle English.

Evolve-evolution: From the Latin evolve meaning to unroll or unfold. Hence evolution, also from Latin evolutio meaning an unfolding. 17^th C usage to describe the development of organisms, or a maturing. Apparently used by Charles Bonnet (1720-1793) and Albrecht von Haller in their theory on homunculus development in human embryos. Charles Darwin did not use the word evolution in the 1859 1^st edition of Origin of Species, but in the 6^th edition (1879) he uses it five times, as on page 201 “At the present day almost all naturalists admit evolution under some form.” And on page 424 he bemoans the fact that he had earlier been censured, but later celebrates general acceptance “I formerly spoke to very many naturalists on the subject of evolution, and never once met with any sympathetic agreement. It is probable that some did then believe in evolution, but they were either silent, or expressed themselves so ambiguously that it was not easy to understand their meaning. Now things are wholly changed, and almost every naturalist admits the great principle of evolution.”.

Ex-: Common word element as in extant, exceed, also as exo-. Derived from the Latin ex- meaning out of, since, but probably PIE in origin as in egh- meaning out. Also, Greek cognate ex and ek. Interestingly, many English words dropped the x before certain consonants, as in emerge, emit, emasculate.

Exo-: Ancient Greek word element, probably of PIE root, meaning out, outside, outer, external. As in exothermic, exotic, exoskeleton.

Experiment: Noun and verb, probably from the Latin experior meaning to gain knowledge by repeating examinations or trials, and the Latin experīmentum and thence Old French esperment somewhere between 12^th and 16^th centuries, meaning a trial or test to gain knowledge, but also used uses of magic. Da Vinci (1452-1519) uses the word experimentum in his ‘Hydraulics’ and the Nature of Water’ Nicholas Steno refers to an experīmentum in his 1669 De Solido.  Francis Bacon makes many references in his 1620 Novum Organum – he refers to experiments in the context of philosophical possibilities and to physical (scientific) trials.

Exponent: From the Latin noun exponentem meaning exponent, and present participle of  the verb exponere meaning put forth. The earliest use of the verb form, as in expound on a topic, was 16^th C. Although the concept of a number being squared or cubed has been known at least since Euclid’s time (about 300 BCE), the first to represent powers as numbers raised to the right of some other number was Nicolas Churquet in 1484 (Le Triparty en la Science des Nombres).  The terms square, cube etc. were also used by Robert Recorde in 1557. However, the representation of the power of a number as in a³ (to reoresent a . a . a) was introduced by Rene Descartes in 1637, in his La Géométrie.

Extant: (adjective) 16^th C from the Latin extantem and the present participle extare, meaning to stand out or visible. The meaning in a biological evolution context is still living, as opposed to extinct. Darwin 1859 (Origin of the Species) referred to the concept as “living fossils” and “living species” but I cannot find a reference to extant. Charles Lyell in his Principles (1830-33) uses extant to refer to ancient manuscripts, specifically Aristotle (p, 20) and Avicennia (p. 30).

Extinct– extinction: 15^th C from the Latin extinctus meaning to quench, put out, die out, as in hereditary titles, or as in a fire, hence extinguish. It was used as a verb in Middle English (e.g. Shakespeare) but this is now obsolete. Robert Boyle (17^th C English chemist) made regular use of extinction in his Experiments and considerations touching colours (1664) in the context of an extinguished flame or removal of heat. The OED notes a certain R. Fabyan in 1513 using extinction “extinccion” to describe the snuffing out of candles. James Hutton (1795) uses the past participle “extinguished” to describe volcanoes no longer active but not as far as I can see the word extinct. John Playfair’s summary of Hutton’s tome on the other hand uses extinct to described the disappearance of a carnivorous animal (1802, p.465). Charles Lyell (1830-1833; 1837) uses the word several times to described the disappearance of species from the rock record. Darwin’s “Origin” (1859) refers several times to the noun extinction in relation to Natural Selection, but not as far as I can tell to the adjective extinct.

Facies: A term coined by Anton Greely in 1836, from the Latin facies meaning appearance or characteristic. First known use is mid-16^th C in reference to the characteristics of a face. Steno uses this word in a geological sense, but not in the specific way derived by Greely (G. Battista Vai, 2012, PDF available). Example: lithofacies is a later derivative that specifies the characteristics of rocks.

Fahrenheit: The temperature scale devised by Daniel Gabriel Fahrenheit (1686–1736) in 1724, 18 years before Celsius devised the centigrade-celsius scale. However, the first known use of the word Fahrenheit is 1753, 17 years after his death.

False: False has a different etymology to its antonym true. It is from the Latin falsus meaning deceptive, deceitful, untrue, thence to Old French fals, (modern French faux) and Old English fals (also Old English ālēogan, which seems unrelated). Middle English retained fals for the adjective, also the verb falsien – to make false or falsify. The ‘e’ was in full use by the beginning of the 17^th C for the adjective, verb and adverb (e.g. Francis Bacon, 1620 – “…that while we falsely admire and extol the powers of the human mind,”

Farther: In Old and Middle English a variant of further – see further.

Fast: (adjective) From Proto-German fastu and Dutch vast, that originally meant solid, steadfast, firm, constant, as in hold something fast (leading to fasten as in adhering or afixing).  Thence to Old English fæst (also snel). The semantic change to meaning rapid or quick may have evolved in a subtle way from expressions like run fast that originally meant running firmly or steadfastly, evolving to a meaning of quickness. Fæst is also a common word element in many Old English words such as fæstheald (firmly fixed), fæsthafol (tenacious), fæstrǣdnes (fortitude). Middle English used fast in both senses – firm, constant on the one hand, and quick on the other. In Middle English, words like fastnesse, fasten, and fastrede derive from the sense of firmness (fastnesse as in a stronghold – the Old English word was fæsten), fastrede as in firm council). The verb form to fast, as in abstaining from food, also derives from the original meaning, as in abstaining firmly. cf. slow was also of Proto-German roots.

Fault: From Latin falsus meaning flaw, blemish, and old French fallere meaning to deceive, and perhaps 13th C English faute meaning deficiency. Became part of the mining vocabulary towards the end of the 18^th C, used to describe the displacement of coal seams along a plane. James Hutton (1785-88) used this term, but also used words like shift, throw, or break.

Fauna: The Roman deity Fauna, a goddess of Earth and fertility, was the daughter of the god Faunus, a deity of forests and fields – also forest spirits or Fauns. It may have PIE origins. The word was popularised by Linnaeus in his Systema Naturae, 1735 and refers generally to the animal world. Cf. flora, also used by Linnaeus.

Feldspar: From Old German feld or field plus spath meaning spar, and the Old German feldspath. Spar is from Proto-German sparron. The English form feldspar is from the Old English spӕr meaning a mineral that splits into spear-like splinters.

Find: (verb) From the Proto-German findan meaning to discover thence Old English findan and Middle English findan with alternative spellings fynden, fynt, fint, and the past participle funden or found.

Fine: (adj) From the Old French fin, from the Latin finis or finem meaning end, limit, border, or boundary, or the verb finire meaning to finish or end. The Middle English verb is finen that is probably the source of finish, final. Also confine meaning limited to or having boundaries. 13^th C and 14^th C meanings extended to (moral) faithful, pure, or true, which also gave us the sense of well or skilfully made. The context as a payment for misdeeds is Medieval. James Hutton (Theory of the Earth, 1795) and Charles Lyell (Principles of Geology, 1837) used fine to describe sandstone, chalk etc. but not the compound adjective fine-grained. As a defined sediment grain size look to Udden (1914) and Wentworth (1922), but the term fine-grained also extends to other rock types, particularly igneous, wood is probably older.

Fiord-fjord: From old Norse fjörðr meaning a narrow inlet, and old German ferthuz meaning a place to negotiate. Common variations are Danish and Norwegian fjord and fjärd, Scottish firth, German förde, and Icelandic fjardur. The geomorphological meaning has morphed to include a glacial origin, as in narrow, glacially carved troughs that have access to the sea.

Fire: Perhaps one of the first words ever invented. It has a long history. The PIE word paewr- gave rise to Proto-German fur and Old English fyr and fieren-. Scandinavian and western Europe words had spellings that obviously stem from these early roots. Old English derivatives include ǣledfȳr (flame of fire), bǣlfȳr (pyre), bēacenfȳr (beacon), fȳrbǣre (fire-bearing). Middle English noun versions include fur, fyre, fyr, fuyr, fier, and the adjective fyry (fiery). The modern version arose about the 16^th C when the ‘e’ and ‘i’ were reversed, except in the word fiery (a Middle English spelling). Aside from all the figurative uses of fire, the word was commonly used to describe several natural processes involving heat, including volcanic eruptions. The volcanological term fire fountain is based on comparisons with natural and artificial columns or sprays of water.

Flood: Noun – from PIE plewd and proto-German floduz, then German flut, to Old English flod meaning flow or deluge as in a river or the seas, as in Chaucer’s The Monks Tale (~1370) – And in balance weyen ech montayne, (And in a scales weigh each mountain) And alle the floodes of the see restrayne. (And all the floods of the sea restrain). The Biblical Noachian deluge is described as a flood in the King James translation (published 1611), for example “And the flood was forty days upon the earth; and the waters increased, and bare up the ark, and it was lift up above the earth.” Genesis 7: 17

Flora: From the Latin flora, and Flora who was the Roman goddess of flowers. Her Greek name was Chloris (or Khloris). Popularised by Linnaeus in his published series Species Plantarum, published in 1753 in which he names all genera known at that time. Here’s the link to Volume 1.

Flow: The verb form is from old English and ancient German flowan meaning to issue, move as a liquid or gas. The noun form is usually qualified by another noun or adjective, as in lava flow in Hutton (1785) and Playfair (p. 263, 1802). Leonardo da Vinci also describes river and canal flow, the action of water in A book of the origin of rivers that flow from the high tops of mountains (c.1500). Also used in the sense of one thought flowing to another (e.g., Antoine Lavoisier – Elements of Chemistry, 1790).

Fluid: From Latin fluidus and French fluide meaning to flow. Used by Isaac Newton in his Lemma III in a fluid-solid context with reference to Earth’s axial tilt (Principia, 1687). Presumably this context in English predates this publication.

Fluvial: Adjective, from the Latin fluvialis the descriptive form meaning river-like, from the noun fluvius meaning river. Its use in a geological or geomorphic context is uncommon until the early 20^th C. Important scientific contributions by the likes of James Hutton (1795) and Charles Lyell (1830-33) do not use the word fluvial but make frequent reference to rivers. Likewise, icons of geomorphology such as G.K. Gilbert in the 1880 2^nd Edition of his classic Report on the Geology of the Henry Mountains where he theorized on the mechanics of stream processes, does not use the adjective fluvial, but river more than 40 times (free access on Google Classics).   William Davis in his classical development of The Geographical Cycle (1899) uses the word river many times, but not fluvial. Joseph Barrell (1917, PDF) in his RHYTHMS AND THE MEASUREMENTS OF GEOLOGIC TIME refers to fluvial in the context of erosion and denudation.

Flysch:  Some authorities indicate it is from Swiss but used in a German context; others suggest it is originally German. In common language it means split. In the 19^th and 20^th centuries it was used to refer to a thick succession of sandstone and shale in deposits associate with the European Alpine Orogeny. That it now commonly refers to deep water deposits is a 20^th C revision. Flysch sandstones were key to later recognition that they were deposited by turbidites (Kuenen and Migliorini, 1950).

Foreland: Its root is old English for- or fore- meaning before, in front of. But not in use until about 19^th C. In geography it refers to a promontory or land in front of a mountain range, as in North Foreland, a promontory in Kent (South England) and referred to in Lyell’s Manual of Geology, 1855. In geology it generally is used in conjunction with hinterland; a foreland in modern context is commonly a region of active, or once active tectonics or sedimentation.

Form: From the Latin noun forma, meaning shape, contour, outline or figure. Thence to Old French forme and fourme. It has multiple meanings from the 13^th C on, including theological, philosophical and metaphysical forms, such as those of Plato, or having form in the context of etiquette or social nuance. It is also used as a word element, as in conform, inform, formation.

Formal: From the Latin adjective formalis, and the noun forma, meaning shape, or figure. Thence to Old French formal and formel meaning having proper form. The Middle English adjective forme meaning first, figure or shape, or form. Informal uses the word element in- as the opposite sense.

Formation: From Latin participle formatio (a shaping) of the verb formare. Informal use in geology referring to the growth or development of something (pretty well anything solid, liquid, or gas) dates back to 14^th C in English usage, although Old French use of formacion may be as early as 12^th C. James Hutton’s Theory of the Earth (1795) makes frequent use of this context. Lyell’s Principles (1830-1833) employs a Coal formation or gneiss formation in the context of a body of rock. Abraham Werner (1749-1817) also used it in this sense in his Neptunist tomes on the origin of the Earth. Its formal use became increasingly important through the 19^th C and early 20^th C. Formal definitions were codified in 1976 in the International Stratigraphic Guide, and a bit later (1983) in the North American Stratigraphic Code. A formation is broadly defined as a mappable body of rock based on rock properties and the boundaries of the body of strata, volcanic rock etc.

Fossil: From the Latin fossilis meaning dug up or unearthed. Used by Leonardo Da Vinci (1452-1519) to describe shelly material (bivalves, corals) found on mountain tops, and who wondered about ancient seas and ancient life forms. Agricola too, in his 1546 treatise De naturium fossilium, ponders organic origins. Despite these leaned expositions, the word at this time was used for almost anything ‘dug up’; explanations generally insisted on inorganic or mineral origins, even for excavated shells and bones. This usage continued well into the 16^th C, although 17^th C luminaries like Nicholas Steno, Antoine Lavoisiér, and Robert Hooke also began to argue for organic origins – as the remains of former life. Their interpretations were slow to take hold – after all, pre-existing life forms did not fit the accepted theological dogmas that incorporated the Noachian Deluge. However, by the late 18^th C (e.g., James Hutton, Mary Anning) and the early 19^th C (e.g., William Smith, Charles Lyell, Charles Darwin) the modern usage of the word fossil had become entrenched.

Fracture (noun) From the Latin fractura to Old French fracture meaning a break. The Latin verb is frangere. According to most reports, it mainly referred to broken bones in the 15^th C. However, Georgius Agricola in 1556 uses infractus in a more figurative sense in “Ausonis ora tumet bellis, terra Attica cultu, Germanum infractus tollit ad astra labor.” (The shores of Auson swell with wars, the Attic land with culture, unbroken labor lifts Germanus to the stars.” A translated tract from his De Re Metallica also refers to breakage of rock “…where the vein is seen to be seamed with small cracks, they drive into one of the little cracks one of the iron tools which I have mentioned; then in each fracture they place four thin iron blocks, …”). More frequent reference to rock and mineral breakage occurs from the 17^th C.

Frost: From the Proto-German noun frustaz and verb freusanan meaning to freeze, which is similar to Old English freosan and froren (that actually sounds like frozen). The Old English nouns were forst  frost, fyrst, and gicelgebland that has roots in the Old English word for glacial (gicelig). Hence hrīmforst (hoar-frost) – The Middle English for hoar-frost was Ryme.

Froude number: Named after William Froude (1810-1879) who in 1861 experimentally determined an expression describing the characteristics of flow, including surface waves and bedforms, as the ratio between gravitational forces and inertial forces. The number defines two primary domains of surface flow – subcritical (or tranquil) and supercritical flow.

Full: Full has a long and varied etymology, used at one time or another as an adjective, noun, verb, and adverb. Its foundation as an adjective was probably the Proto German fullaz and Old German ful, to Old English full then Middle English fulle and fylle. meaning replete, volume, or entire. The adverbal form in Old English was the same as Old German ful, that continued into Middle and later English in words like fully, and compound adjectives like full blooded and full moon (the plural is full moons).

-full: Originating from the adjective full, with similar etymology from the Proto German fullaz. The Middle English suffix –ful, is used to create nouns such as in thoughtful, bashful, helpful, faithful.  compound nouns use the Old English form -full, as in bank-full.

Function: (noun) From the Latin functionem (or function) meaning a performance, purpose, or something undertaken, to French function. Gottfried Leibniz was the first to introduce the term in 1673 in his development of calculus. Euler introduced the notation f(x). In mathematics it is a written expression that defines a relationship dependant and independent variables. For the simple equation of a straight line y = mx + c, y is the variable dependant on whatever values of x are applied (x is the independent variable). Thus, for any value of x there is a unique value of y. for the equation above, function y(x) = mx + c and the slope of the line is given by dy/dx.

Further: (adverb) May originally stem from PIE, but more generally know from the Old English furdor or fordor meaning forward, beyond, or more distant. In Middle English furdor continued to be used but was replaced with forther. The verb form forther was also used meaning to go further or to aid. Hence further in later English. The English farther became a variant of forther and further, but it meant basically the same thing. American English adopted further to mean a principle, or in addition to, rather than farther which was restricted to meanings of distance, but there appears to be no real etymological reason for the separation of meanings.

Gene-: From PIE root genə– and gen-, meaning to give birth, or beget as in all those Biblical begets and begots. Hence variations like genetic, genus, generation, genesis having Latin roots.

Genus: (plural genera) From Latin genus meaning of birth, kind (as in association of like beings or things). Mostly used in biology and paleontology (as in taxonomy), but also in meteorology, as in cloud genus. Joseph Pitton de Tournefort (1656–1708) was one of the first to introduce the concept in his study of plants. But it was the Swede Carl Linnaeus who in 1753 introduced the binomial taxonomic system of genus and species in his Species Plantarum – you can see facsimiles of these volumes at the Gutenberg ebook library.

-geny: In geology, mostly used as a suffix, from the ancient Greek genesis meaning origin or creation. Also, the adjective form -genic. Examples: Progeny (descendants), Phylogeny (of evolutionary descent), autogenic.

Geo- From the Greek geo meaning Earth, countryside. Examples: geology, geoscience, geomorphology

Geochemistry: The term coined by Swiss-German chemist Christian Schönbein in 1838 as the chemical science of Earth and the planets (Schönbein also discovered ozone). It is a fundamental part of modern Earth sciences. The prefix Geo means of the Earth; in the 16^th C the word chemistry became a more refined version of the word alchemy – the latter was concerned with elemental and mineral transformations but also invoked components of potions and incantations. The word chemistry became scientifically more acceptable in the 16^th and 17^th centuries.

Geology: In the 16^th and 17^th C the term mineralogical geography was used by Europeans to describe rocks in the surface and subsurface. About this time the term geognosie was introduced by German miners and naturalists primarily as a descriptive form of knowledge. The word Geology was tentatively introduced by Jean-Andre de Luc. A Swiss naturalist in 1778. (David Bressan, 2019).

Geometry: From the Greek geo- meaning Earth or things related to Earth, and –metria meaning measure. The geometry derived by the Greek mathematician and philosopher Pythagoras (about 570 – 495 BCE), is an extension of the measure of the Earth as angles and lengths of two- and three-dimensional objects.

Geophysics: A combination of the Greek geo- and physika. It was coined by Julius Fröbel (1805–1893), a German geographer in – Mittheilungen aus dem gebiete theoretischenerdkunde or Communications to the field of theoretical geography, published in 1834. His intended meaning – to gain an understanding of the physical Earth using experimental physics. However, the overall concept may have been introduced by a French physicist Aimé-Henri Paulian (1722–1802) in his La physique terrestre or Earth physics (1761).

Glacier: From the Latin noun glacies and adjective glacialis meaning ice, to Old French glace and later French glacier and glaciere. The Old English adjective form was gicelig (glacial). First use is commonly quoted as 1744, but the relevant document is obscure. However, a few years later (1776), traveller and writer M.T. Bourrit  published A relation of a journey to the glaciers in the Dutchy of Savoy that is an account of several glaciers in that region.

Glass: (noun, adj) There is a PIE root that emphasizes shininess, or gold-like lustre, thence Proto-German glasam, and Old English glæren meaning vitreous or glassy or glæsen meaning glass. Glæs is also an Old English element for words like glæsful (glassful) and glæsfæt (as in a glass vessel). Middle English glas (glass) and glasen (made of glass) dropped the ae digraph. James Hutton (1795) refers to the ‘glassy’ surface of bituminous coal, and also to ‘melted glass’ where he contrasts crystal forms that precipitate from water, to melting under pressure. As a volcanic product the word glass goes hand-in-hand with obsidian, defined in Lyell’s Glossary (in the Principles, 1830-1833).

Golden spike: The original Golden Spike was the last spike used to complete the American Transcontinental Railroad, that jointed the Pacific and Atlantic coasts. It was driven into the track at Promontory Summit, Utah on May 10, 1869. The western leg of the track was constructed by Union Pacific, and the eastern leg by Central Pacific Railroad (from the Library of Congress records – ). The terms is also used in stratigraphic successions to denote a Global Boundary Stratotype Section and Point – whether the term was borrowed from the railroad episode is debated. Hollis Hedberg is credited with formally introducing the concept in 1977 (after much discussion and argument) (Walsh et al., 2007).

Grain: From the Latin noun granum meaning a seed or kernel, thence Old French grain or grein, and Old English grot meaning particle, hence sandgrot – a grain of sand. The Middle English greyn and greyne could also mean seed-like bits of salt or sand. Its geological context as in clastic particles was in common use by the time James Hutton published Theory of the Earth (1795).

Grain size: A phrase based on the standard meaning of grain. One of the earliest classifications of grain size still in use today was Chester Wentworth (1922; Table 1) who modified a previous scheme by Johan August Udden (1914), defining size ranges in millimetres for clasts ranging from boulder (bowlder) to clay. The size categories are arranged in geometric progression.   Its context as a weight measure was based on a single grain of wheat, hence a grain of lead, or grain of powder.

Granule: The diminutive of the Latin root granum as in grain. According to Wentworth’s original classification (1922) granules range in size from 2-4 mm diameter.

-graphy: From the Greek -graphia, and French -graphie, meaning the “description of”, as in petrography, geography, hagiography.

Gravel: From the Old French grave meaning sand or shore, thence Old French gravele. Old English equivalent was grēosn meaning pebble, or consisting of pebbles, that morphed to grauayle in Middle English. James Hutton (1795) frequently used gravel as a descriptive term for different kinds of puddingstone (he did not use the term conglomerate). Chester Wentworth (1922) used the word in his formal scheme for grain size but reserved it for non-indurated coarse-grained aggregates of granules, pebbles, cobbles, and bowlders (sic). Modern usage generally follows Wentworth’s scheme.

> < Greater than/less than: Commonly attributed to  Thomas Harriot (1560-1621) in his Artis Analyticae Praxis ad Aequationes Algebraicas Resolvendas that was published posthumously in 1631. But the symbols are not found in Harriot’s actual writing. Instead, Harriot graphed two figures that look like wedges with closed ends (so he did use a symbol, just not the one we are familiar with). The publisher-editor may have added the > and < versions. The explanation (1631) for < was “Signum minoritatis ut a < b significet a minorem quam b.” (The minority sign such as a < b means that a is less than b.). Pierre Bouguer (1698-1758) added a modification as ≧ for greater than or equal to, that subsequently became ≥.

Grit: From the Proto-Germanic greutan meaning crushed rock, and Old English greot, meaning sand or gravel, that carried through to Middle English greot with variations as greit, greete, and grith. Wentworth (1922) specifically excluded grit from his grain size scheme because previous usage included both coarse and fine granular material. One of the earliest uses in a geological context in England was by John Whitehurst who published An Inquiry into the Original State and Formation of the Earth, 1778, who named the (Carboniferous) Millstone Grit, a stone that had been used to mill grain since Roman times.

Gymnos-: From the Greek gymnos meaning naked. Thus, gymnosperm refers to naked seed(from the Greek sperma meaning seed).

Gyre: From Greek gyros and Latin gyrus meaning circle (noun) or turning in a circle (Latin verb gyrare). Applied to ocean currents – there are 5 main ocean gyres North and South Atlantic, Pacific Ocean gyres, and Indian Ocean gyre.

-hedral: Derived from the Greek word element -edron meaning sided in the context of solid geometry, and hedron meaning seat. As in octahedral (8-sided).

Hetero-: Word element from the Greek heteros meaning another, other, or different. Hence heterocyclic, heterotroph, heterosexual.

Hinterland: From German hinter meaning behind. In late 19^th C it had a commercial and geographical context, as in behind a coastal port or centre of commerce. It was also used by European nations to describe colonised land, as in commodity-producing hinterlands. In geology, it also refers to countryside behind a coast, or behind a foreland.

Hjulström diagram: Named after Filip Hjulström (1902-1982) who experimentally determined the velocities required to initiate sediment particle movement along a bed. It was published in 1939. The diagram plots flow velocity at the point of initial movement against grain size. Hjulström, F. (1939). Transportation of detritus by moving water: Part 1. Transportation. In P. D. Trask (Ed.), Recent marine sediments. A Symposium: Tulsa, Oklahoma (pp. 5–31). Tulsa, OK: AAPG.

Holo-: A word element (prefix) from the Greek holos meaning complete or entire. As in Holocene, holocrystalline. Apparently there is no link to the word whole.

Homo-: A word element from the Greek homos meaning the same, equal, or as one. Hence homogenous, homotaxial (similar arrangement of strata, fossils).

Hydro: From ancient Greek hydor, meaning water, that forms the prefix for hydrometer, hydrology, hydrogen, hydrothermal.

Hyper-: Originally from PIE upper meaning over, thence Greek hyper meaning over, or beyond. Hence hyperpycnal, hyperconcentrated, hyperactive.

Hypo-: Like the word element hyper, originally PIE upo meaning beneath or below, thence Greek hypo meaning under, below, beneath. Hence hypopycnal, hypocritical (beneath the value of critical), hypoxia (beneath the level of sufficient oxygen).

Hypsi-: From Greek meaning high, top, above. As in hypsithermal meaning climate optimum and thermal maximum. Also as the Greek hypsos from which we derive hypso-

Hypso- From the Greek hypsos meaning height, above. Hence hypsometric (adjective) and hypsometry (noun) meaning the measurement of land (positive) and seafloor (negative) altitudes relative to average sea level.

Ibid: From the Latin ibidem meaning “in the same place.” It is generally used in publications to abbreviate citations of a paper or report that appears more than once in the text or in footnotes. Example: N. Chamberlin et al. ibid.

-ic:  A word ending that creates adjectives with the general meaning “in the manner of”. From old French. Geological examples: volcanic (pertaining to volcanoes), acidic (as an acid), benthic (in the manner of the benthos).

Ice: From the Proto-German is- and ice, that carried through to Old English is yce and yse (as in the Anglo-Saxon poem Beowulf). The Middle English forms included is, yce, yse, and ice.

i.e.  From Latin id est or that is, added to a sentence or paragraph as an additional explanation, qualification, or restatement of a preceding discussion, comment, or argument. The general rule is to use periods, as in i.e. rather than ie, and that it is part of a sentence rather than beginning a separate sentence.

Igneous: From the Latin igneus meaning on fire, or hot. James Hutton (1785; Playfair, 1802) used the word frequently, commonly in the phrase igneous consolidation, where he was comparing the solidifying of lava-magma with aqueous consolidation. This was an important concept Hutton developed to explain the origin of granite. The word came to prominence in the late 18^th – 19^th C in the debate between Neptunists (Abraham Werner) and Plutonists (Hutton, Lyell).

Impact: (verb) A relatively young word, originally from the Latin impactus meaning to force or drive into something. To strike against is probably mid-late 19^th C, as is the past participle impacted, as in teeth. The noun form is probably 18^th C. One of the earliest references to meteorite craters as impact structures was G.K. Gilbert in 1892, in a paper read to the National Academy of Sciences – The Evolution of the Moon “‘The origin of these craters has been the subject of many theories. … and to the impact of bodies from without. Personally, I favor the last mentioned”. (in: Astronomical Society of the Pacific, Vol. 4, No. 26, p. 263-264). A few years later D.M. Barringer (1905) in a paper on the Coon Mountain crater, later named the Barringer Crater, in Arizona, refers to the crater “…produced by the impact of an iron body falling out of space,” (Proceedings of the Academy of Natural Sciences of Philadelphia, Vol. 80 (1928), pp. 307-311 – OA.)

In-: As a prefix, it supports two different meanings. (1) To denote opposite or without, as in inadequate, independent, inept, from the Latin in- meaning opposite, with the Greek variant an- and Old English un- as in unstable. (2) to denote something within or into, as instigate, investigate, that in Old English was written as on- and Middle English as en-, such that there can be two variants with words like enquire and inquire.

∞ Infinity: The symbol representing infinity in mathematics was invented by English mathematician John Wallis in 1665. It is defined in his DE SECTIONIBUS C O N I C I S nova methodo expositis tractatus, (Treatise on the conic Sections) on p. 4, Proposition 1 as “(efto enim ∞  nota numeri infinitis)” (for ∞ is the sign of infinite numbers).

Integer: From the Latin verb tangere meaning to touch and the negative word element in-, thence to the noun form of the Latin adjective integer meaning whole or complete. Hence, a whole or complete number. The history of the formal use of whole numbers goes back to the ancient Greek, Indian, Babylonian mathematicians, and others. Possibly the first use of the word integer in English is 16^th C. Thomas Digges A Geometrical Practise Named Pantometria (1571) contains reference to “integer not fraction” that delineates the two types of numbers. Isaac Newton’s Principia (written in Latin) uses integer and the Latin plural integrorum in the sense of being part of a whole, as in “Igitur motus omnes, qui de locis motis fiunt, sunt partes solummodo motuum integrorum et absolutorum, et motus omnis integer componitur ex motu corporis de loco suo primo” or “Therefore, all motions that arise from moved places are only parts of whole and absolute motions, and every whole motion is composed of the body’s motion from its first place.” Leonard Euler in 1765 in Elements of Algebra defines positive and negative integers (the link takes you to the 4th Edition, 1828).

Inter-: A common word element from the PIE enter, and Latin inter meaning between or among. Use of the Old French entre for many (but not all) words stopped in 15^th – 16^th C when it was deemed more correct to use the Latinized version, as in interval, interest, interregnum. Geological contexts like interbed are 20^th C.

-ion: A common word element (always a suffix) that creates a noun from the associated verb. From Latin -ionem and -ionis, and thence French -ion. As in direction, sedimentation.

Ion: A stand-alone noun and chemical term denoting an atom that has lost or gained an electron, producing a positive or negative ion respectively. The term was suggested by polymath William Whewell to Michael Faraday who formalized it in 1834. From the Greek ion meaning to go (in this case towards). Hence Cation, anion.

Iron: Most etymological texts put the origin of the word iron as Celtic, thence Proto-German and Old Saxon isarn, and Old English iren, thence to several forms in Middle English – Iren, yren, irun, and yrun. Some of the earliest meanings were of strength and power, but this morphed into the metal, particularly weapons and agricultural instruments by Old English times, as evidenced in the poem Beowulf (probably from 8^th-10^th C) where iren is used many times to refer to metal objects, principally swords and knives. Note that the metal itself was discovered several thousand years ago. The chemical symbol Fe is from the Latin ferrum and was first used by Jöns Jacob Berzelius (1779-1848) who devised the letter abbreviations for chemical elements that we use today.  

-ise or -ize? Choosing one or the other is a common problem for writers who span British and American styles. From a purely grammatical perspective, the suffix …ize is correct for words having Greek roots.  The …ise is from French. But the rules are not always applied. For example, organize/organise has a Latin root, but many insist on organize. Some British publishers require the …ize suffix. Examples: Televize/televise (tele is Greek, but vision has a Latin root); systematized (from the Greek root systemat-), criticize (from Greek kritikós). See also colour – color.

Iso- From the Greek word īsos meaning equal. One of the earliest uses in geology was introduced by C.E. Dutton who coined the term isostasy to describe the state of balance between the crust and mantle.

Isobath: From the Greek iso meaning equal, and bathos meaning depth. A synonym of contour but usually reserved for subsea or lake bathymetry. The earliest known map showing a sea floor isobath is of the Gulf of Lion by Luigi Ferdinando Marsigli (1658-1730) – Histoire physique de la mer in which his Carte du Golfe de Lion  (Gercsák, 2009;     Acta Geodaetica et Geophysica Hungarica). Marsigli obtained the water depths using the standard sounding method of the time – tossing a weighted rope overboard.

Isopach: From the Greek iso- meaning equal, and pakhus meaning thick. The geological context refers to contour maps of rock units based on their thickness. The term Isopachous stems from this general meaning and refers to an equal thickness of crystals in a rock cement.

Isostasy: The term introduced by C.E. Dutton, initially in a footnote to an 1882 publication, then formally in 1889 (On some of the greater problems of physical geology). It describes the state of balance between the crust and mantle. From the Greek īsos meaning equal, and stasis meaning a state or condition of something, or standing still.

Isotope: From Greek isos meaning equal, and topos meaning place. It was coined by English chemist Frederick Soddy in 1913 because the isotopes of any element occupy the same place on the Periodic Table as the parent element (see his Aberdeen Addresses, 1920).

-ite: A noun-forming element, originally from the Greek itis and ites, and Latin ita. The most common suffix for mineral names (calcite, augite). Also used in ancient times to denote ethnic groups or tribes, such as Hittite; hence it’s use in paleontology for groups, or tribes like Trilobite, Ammonite.

-ium: From the Latin suffix -ium used to name metals like iron (ferrum). It is commonly used as a suffix for many chemical elements. Humphrey Davy in 1807 was one of the first to use the suffix in naming chemical elements like sodium, calcium.  In 1811 Jons Berzelius (1779-1848) suggested naming all elements using their Latin derivatives.

Joint: (noun) A structural term that refers to planes of breakage or splitting in hard rock, but its origins lie in 13^th C anatomical notation, as in the contact between bones. From Latin iunctus meaning connected or joined, that somehow changed to joint in Old French. The meaning was extended in the 14^th C and onward to include the connected parts of plants and insects. Georgius Agricola describes commissurae saxorum in his De Re Metallica (1556), that translates as rock joints, seams, or cracks.  Several other meanings developed from about 19^th C on, such as slang for a building, prison, a smoking den, a marijuana cigarette). As a rock-structural term, it implies the connection between two rock faces.

Jökulhaup: (also Jökulhlaup) A glacial lake outburst. From Icelandic jökull meaning glacier, and‎ hlaup meaning flood.

Lacuna: A word used by H.E. Wheeler in 1958 to describe a stratigraphic time gap. It is derived from Latin lacus (lake) modified to lacuna meaning pit or gap. English borrowers in the 17^th C used it in a rhetorical figurative sense as something missing in written text. English plural is lacunas.

Lagoon: Originally from Italian laguna to describe the Venice coast, borrowed by French (laguna), both from Latin lacuna meaning pond or pool that is a variation of the Latin lacus meaning lake (lacuna also means gap). Captain James Cook introduced the word lagoon to English from his travels, to describe the seawater behind coral reef atolls (late 18^th C).

Land: A noun and verb; both forms probably derived from Old English (12^th C and older) and/or old German, as land or lond, meaning ground, or portions of Earth’s surface – probably the visible surface. The verb form, as in the present participle landing, probably derives from an active approach to or arrival on land. The verb form to land (a punch) also derives from the idea of place. As a noun it is used as a word on its own (Gondwana land), a prefix (as in landward), a suffix (as in island, mainland), and a pronoun as in Iceland, Poland, New Zealand, Finland.

Late: (adj) From the Proto-German lata- and Old Norse latr meaning lazy, slow, sluggish, thence Old English laet where the meaning morphs to after some time, or at the end of expected time. Spelling late by Middle English. Late refers to the end of a particular period of time formal chronostratigraphy. late Charles Lyell was probably the first to present a hierarchical chronostratigraphic chart – his 1855 chart uses mostly Upper and Lower designations, except for the Pliocene where he indicates “older” and “newer” Pliocene.

Latitude: From Old Latin stlatus, and later latitude meaning extent, size, width, and 14^th C Old French latitude. One of the earliest uses in English is from Geoffrey Chaucer’s Treatise on Astrolabe (Part II, Section 17, about 1400), where the word refers to position on a map (he also uses the word longitude) – an excerpt “And his latitude is rikned after the quantite of his declinacion, north or south to-warde 20 the poles of this world; as thus. Yif it be of the sonne or of any fix sterre, rekene his latitude or his declinacioun fro the equinoxial cercle; and yif it be of a lanete, rekne than the quantitee of his latitude fro the ecliptik lyne.”  

Lava: Probably from the Latin verb lavare meaning to wash, that in Italian became lava, from the Neopolitan lave, that originally referred to water torrents or vigorous stream flow. It was applied to molten lavas effused from Vesuvius because they appeared to flow like rivers. One of the earliest usages in a magma context was in the writings of Francesco Serao (1702-1785) about Vesuvius eruption in 1737: Reale Accademia delle Scienze Fisiche e Matematiche di Napoli. Istoria dell’ incendio del Vesuvio accaduto nel mese di maggio dell’anno MDCCXXXVI. Naples: Nella stamperia di Novello de Bonis, 1738. (Royal Academy of Physical and Mathematical Sciences of Naples. History of the fire of Vesuvius that occurred in the month of May in the year 1736. Naples: Printed by Novello de Bonis, 1738). The text is Latin; lava flows are referred to as torrents: “praterquam quod oculatus tefììs Jofepbus Macrinus fj) confìrmat, lufrantì Jthi ìnfulam non obfeura corum torrentium, quos Lava reacalo fermone dicimus,” – “besides what Josephus Macrinus, who was an eyewitness, confirms, the torrents, which we call the Lava,…”

Lava tube: see the entry for tube. The earliest references I have found to lava tube are Chester Wentworth (1925), and Henry Palmer (A fossil lava-tube; Journal of Geology, 1929, OA) for Hawaiian examples. Wentworth called them “lava tube casts.”

Law: A word with a fairly complicated history, but the basic concept of rules and authority stem from the PIE legh meaning lay or lie (as in lie down) that gave rise to two words – law and lay, via Proto-German lagam. The Old English lagu and word element lah were probably derived from Old Norse lagu meaning law, via the Proto-German. The Old English ӕ also meant law, associated with the divine, covenant, and was used widely as the root for words like code of law (ǣriht), law-breaker (æslitend), legal (ǣwlic). The Old English lah was also a root for words like legal (lahlic). The Middle English law was a word element for lawful (laweful) and lawless (lawelese). The scientific context of Law was derived from theistic laws of nature, but deviated from it such that Laws made, and needed no reference to God. One of the earliest uses in a semi-modern sense was Francis Bacon’s Novum Organum (1620), where he frequently mentions ‘laws’, as in “It is best to consider matter, its conformation, and the changes of that conformation, its own action, and the law of this action or motion;” Nicolai Steno’s 1669 principles of stratigraphic superposition are sometimes referenced as Laws, but he did not use the Latin equivalent – lex. The foundational Laws of Thermodynamics were discovered between the 1840s and 1912.

Lead: (verb) From the Old English lædan, and Middle English leden, or lede meaning to go forth, in front, first place, as in Chaucer’s (1340-45 – 1400) “For she hirself wolde al the contree lede.”          “For she herself wanted to rule all the country.”. The noun form as in being at the front, also Middle English leed and lede again in Chaucer’s “Til deeth departeth hem, this lyf they lede.” Until death departs them, this life they lead. (both quotes from The Man of Law’s Tale).   (translations from Harvard’s Geoffrey Chaucer Website)

Lead: (noun) A soft metal (chemical symbol Pb), from Old English lead, Old Irish (Celtic) luaide, also refers to a vessel (e.g., drinking cup). The Middle English form leden also means leaden as in heavy. Black lead was a Middle English name for graphite and chimney soot – from this we get the first use of pencil lead in 1857 (OED) – the pencil invented by Nicholas-Jacques Conté in 1795.

Length: As a measure of distance is probably from Proto-German and thence to the Old English lengðu. In a figurative sense, as in the lengths on will go… is Shakesperean or older (mid 17^th C).

Less: From Proto German laisizan, Old English læs, and Middle English lesse or lasse meaning fewer or smaller.

-less: An adverb-forming word element derived from less, that means devoid of, lacking, free, or vacant – as in formless, regardless, structureless.

Lies, Damned Lies and Statistics: The number of people who have quoted this phrase since the early 1800s makes it difficult to decipher the first utterance. Some of the eminent figures it has been attributed to include Lord Courtney, Mark Twain, Lord Balfour, and Benjamin Disraeli. According to one analysis, it probably was no earlier than 1886 (Dept. of Mathematics, University of York, 2012). Note that the first use of the word statistics in English is 1770 according to the OED.

Lime: From PIE root lei-, thence Old English lim and proto-German leimaz meaning chalky, cement, mortar, also Latin limus meaning mud, slime. The Latin calcis meaning limestone, lime, and from which we get calcareous and calcite. Antoine Lavoisier describes in Sect. XVII. Observations upon Carbonic Acid, and its Combinations.(1789), the effect of adding acid to lime-bearing rocks to produce a gas (CO₂ – although he didn’t know the gas composition at the time).

Limestone: A stone that produces lime when burnt, hence lime-burner or kiln in 13^th and 14^th C. The Oxford English Dictionary claims the earliest use is 1523, in the writing of John Fitzherbert (I was not able to find this reference). However, I did find a 1607 reference to burning limestone in John Norden, The surveyors dialogue (London: Hugh Astley, 1607), p. 228; Fussell, Old English farming books, p. 100. From Latin calx. James Hutton in 1795 pondered the origin of limestones, particularly those containing fossils.   The more modern use of limestone also occurs many times in Charles Lyells’ Principles.

Limit: (noun) From Latin limitem (limes) to Old French limite in 14^th C meaning a boundary, or as far as, to limit or lymit in Middle English. In mathematics the concept of limit probably derives from Euclidian geometry, then later in the Enlightenment by Grégoire de Saint-Vincent in 1647 to define the terminus of a geometric progression. Newton’s Principia also defines the concept of limit where ultimate ratios approach a limit rather than being actual numbers. From this derives the concept of limit in calculus.

Line; -line: (noun, verb, adjective) From Latin linea meaning a string, thread or limit, and adopted in 12^th C old English (as in row, rope, series) and old French ligne as in string, guideline, descent (as in lineage). Has morphed into various usages such as line of credit, shipping line, down the line.

Litho-  A word element from the Greek lithos meaning rock or stone. Examples: lithofacies, lithology, lithostratigraphy.

Load: From Old English (pre 12^th C) lode, or lade, meaning to add weight to something or someone. From 13^th C on the meaning morphed to include the load of a firearm, and psychological or emotional load derived from stress. In geology, the meaning of load centres around the application of stress, as in tectonically emplaced load, hydrostatic and lithostatic loads, sediment load (that accrues in a sedimentary basin), but includes sediment load (as that carried by a river).

Locus: From Latin locus (plural loci) meaning place, country, route, and also of rank, position, and locus of control (of people). The mathematical principle may have been discovered independently by Pierre de Fermat, and Rene Descartes, both 17^th C French mathematicians. Fermats major work also titled De Locis Planis that was complete in 1630, was a restoration of a work done more than 1800 years earlier by Greek philosopher Appollonius (about 240 BCE). His Introduction to Loci was published posthumously in 1679.

Loess: Wind-blown silt and clay sized particles that can form extensive, thick deposits. Mostly found in periglacial regions. The term, based on a Rhine Valley word Löss, was first introduced by Karl Cäsar von Leonhard in 1824 for a yellowish silty loam common in the Rhine Valley (Kölbl-Ebert, 2024). Its extended meaning in a global context was the result of Charles Lyell’s studies, first elucidated in his Principles of Geology in 1833 although its mode of deposition was debated for several decades after. An aeolian origin was first proposed by German geomorphologist Ferdinand von Richthofen sometime around 1872.

Login: Analogous to creating a log, or record of events, dates, etc. such as a ship’s log. The first digital login that also required a digital password was probably an Massachusetts Institute of Technology computer science professor Fernando Corbato in 1961, who needed several terminals to his computer to be accessible by different users – each had their own password.

Longitude: From Latin longitudo meaning length or duration, and longus meaning length. The geographical meaning of great circles from pole to pole is probably late Middle English (14^th – 15^th C). However, measurement of longitude was fraught until the invention of the marine chronometer by John Harrison, the first model constructed in 1735.

Lopolith: The word element lith is from the Greek lithos meaning rock. First used to describe an intrusive rock body by Frank Grout in 1918 in a paper “The Lapolith”, American J Science, p. 516. In this paper he discusses the differences with laccoliths.

Lower: (adj) A different origin to its antonym upper. Probably from Proto-German lega and Old Norse lagr meaning short, humble, lying flat. Middle English froms included lawar, lower, lougher.  The Middle English verb was loure. Other meanings like lower-class probably date from 17^th or 18^th C. Its formal introduction to stratigraphic nomenclature was probably 18^th and early 19^th C.

Lunar: From Latin luna meaning moon, thence to the French lunaire. About 15th C. Also the alchemist name for silver, referred to many times in Chaucer’s Canterbury Tales (late 14^th C).

Macro- The English version morphed originally from ancient Indo-European, to Greek makros, and thence to English. It means large or long. As in macroscopic, macrocosm, macrofossil

Magnesium: Discovered in 1755 by Joseph Black, but named by Humphrey Davy in 1808 after Magnesia, a district of Eastern Thessaly in Greece. Magnesia itself has a much longer history in Alchemy from the Greek magnesia stone or lodestone.

Magnitude: From the Latin magnus meaning great in both figurative and physical senses, thence the Latin magnitudo meaning greatness in size. The Greek form megas gave us the word element mega meaning large or great. The figurative sense seems to be pre-14^th C; the literal translation of Magna Carta is Great Charter, signed by King John in 1215. The Magnitude Scale for earthquakes was constructed by Charles Richter in 1935. The first Magnitude Scale for star brightness was named by Ptolemy in the 2^nd C CE, although development of the scale is attributed to the Greek astronomer Hipparchus in the 2^nd C BCE. The earliest use of “order of magnitude” that I have found is in A Dictionary of Science, Literature & Art (by W.T. Brande and J.Cauvin, p. 385, 1852) in a description of material elasticity. William Whewell in the 2^nd Edition of The Plurality of Worlds also refers to “Applying these considerations to the stars of inferior orders of magnitude…” (p. 325, 1860).

Mangrove: Probably a compound of the Portuguese mangue and the English grove, but may originally have been derived from Malaysian manggi-manggi meaning above the soil. Mangroves are angiosperms that have adapted to shallow coastal marine environments. They usually occur in ‘forests’ and are one of the most productive marine ecosystems on Earth – they are also one of the most threatened.

Mantle: (noun, verb) From Latin mantellum meaning cover or cloak, then Old English mentel meaning a loose covering. Although Andrija Mohorovicic (1857-1936) discovered the boundary at the base of the crust (the Mohorovicic discontinuity) he did not name the underlying mantle. Nor did Jospeh Barrell (1914) who defined the lithosphere and asthenosphere. Arthur Holmes developed his substratum convection hypothesis, (1929), but not until the 1940s did he refer to it as the mantle (A Review oif the Continental Drift Hypothesis. Mineral Mag. London, v. 40. 1029).

Map: (noun, verb) From old Latin mappa mundi meaning ‘map of the world’, morphing in 15^th C English to mapemounde, and French mappemonde, later shortened to map. The Latin mappe means cloth; mundi means ‘of the world’. The oldest known (surviving) map of the world is the Babylonian Imago Mundi about 700-500 BCE. The oldest surviving geological map is the Turin papyrus (1150 BCE) that outlines locations of building materials and gold deposits.

Mare (plural maria): From PIE mori meaning a sea or water body, thence Latin mare meaning sea. Used by Galileo to describe features of the moon (1630).

Mass: Its derivation appears to be related to bread making – from Greek maza, meaning a cake or lump, and Latin massa meaning kneaded dough. The transition to its more modern meaning of a lump, a crowd, a piece of something seems to be the Old French masse. Its use by Isaac Newton extended the meaning to bodies large and small – it is central to his Laws of Motion (17^th C). It is now regarded as one of the fundamental dimensions of matter and motion, along with length and time. The Christian Mass began in the first century CE.

-ment: A common suffix derived from Latin -mentum that was added to verbs to create nouns, indicating the result of some action. Hence ravinement (erosion across a shoreface during transgression), movement, decipherment, sediment.

Meso-  From Greek mesos meaning middle, between. As in Mesozoic (the geological period between the Paleo-zoic and Ceno-zoic).

Meta-: From the Greek prefix meta meaning after. The English prefix commonly means change or alteration. Examples: metamorphism, metasomatic, metastable

Meteorite: From Greek  meteora meaning from high up, from the heavens or sky, to medieval Latin meteorum, and Old French meteore (13^th C). In the context of shooting star is probably late 16^th C. The term betyl or baetyl in Biblical texts is a reference to sacred stones that may be a reference to meteorites, from the Greek baitylia meaning fallen to Earth. Francis Bacon’s Novum Organum (1620; originally in Latin) makes three references to meteors, once in the context of comets, and also as heavenly bodies, as in “in some comets, which hold a place between stars and ignited meteors”.

Metre: From the Greek metron meaning measure, thence French mètre. Became an actual measure in 1670 (French Academy of Sciences), and an international standard of length (SI unit) in 1960. It is currently defined as the distance light travels in a vacuum in 1/299,792,458⁠ of a second (299792458m/second is the speed of light). There have been several iterations of the definition., The spelling metre is congruent with its Latin base. America spells the word as meter.

Meter: The alternative American spelling of metre. For most other users meter refers to a measuring instrument or dial.

-metry: Word element from the Greek metria, thence Latin metria and French metrie, meaning measure, forming nouns like bathymetry, geometry.

Micro-  The latinized version of the old Greek mikros meaning small. Examples: microscope, microcrystalline, microbe

-mict: A Greek word element from mixis meaning mixing, or mingling, or the past participle miktos (mixed), from which the English use mictic was derived in the early 20^th C. One of its original usages was to describe sexual reproduction, but it was soon borrowed for limnological terms like holomict (water stratification), and geological terms like diamict or diamictite (glacial moraine deposits), and polymict (sometimes applied to the composition and provenance of clastic sediments; also monomict).

Middle: (noun) The Old English middel meaning equidistant from two ends or centre, is probably from Proto German midla, that also is represented by European Low countries such as Old Dutch middel and Old Saxon middil. Old English adjective form is midde meaning mid or middle. It becomes a word element for midday – middeldæg, middelfinger, and midnight middelniht. The Middle English spelling remained middel, although the shortened form mid is the same as the modern spelling.

Milankovitch cycles: Named after Milutin Milankovitch (1879 – 1958), a Serbian mathematician and engineer, who developed the mathematical models for planetary orbital frequencies and solar insolation (precession, obliquity, and eccentricity) that provide mechanisms to change earth’s climate at regular intervals or cycles.

Mineral: From 14^th C Medieval Latin, minera meaning a mine, minerale meaning something mined, and mineralis relating to something mined. Thence to Old French mineral. Georgius Agricola’ is regarded as the progenitor of modern mineralogy – his first systematic treatment was De Veteribus et Novis Metallis that was completed about 1546. His De Re Metallica 1552 is probably the more celebrated of his metallogy and mining works. See the translation from Latin by H.C. Hoover and L.H. Hoover, 1950.

Model:  From Latin modulus meaning a small measure; also Old French modelle meaning a scale likeness. One of the earliest uses known is from John Dee’s Preface to Elements of Geometry of the Most Ancient Philosopher Euclid of Magara, by Henry Billingsley in 1570, where Dee refers to a “…Model of a Ship…” “…(in any assigned proportion)”, in the context of geometric proportions. The sense of model here is clearly one of representation and scale, both of which remain important characteristics of modern attempts at modeling. The more figurative meaning of standard (e.g., model of behaviour) is 17^th C, including Shakespearean usage.

Mollusca: (or mollusk) From the Latin mollis meaning soft and molluscus which was adapted from Aristotle’s Greek name ta malakia (meaning ‘soft ones’) and thence French mollusque. Use in early 17^th C referred to Cephalopods and gastropods lacking external shells. In 1758 Linnaeus used the term Mollusc to define one of three orders and in this context included true molluscs as well as soft bodied forms and starfish – the other two orders also contained various molluscs (in the modern sense). Georges Cuvier provided us with the modern usage in his 1795 opus “Second mémoire sur l’organisation et les rapports des animaux à sang blanc, dans lequel on traite de la structure des Mollusques et de leur division en ordre, lu à la société d’Histoire Naturelle de Paris, le 11 prairial an troisième. Magazin Encyclopédique, ou Journal des Sciences, des Lettres et des Arts2: 433–449”. Here he defined them as “…characterized internally by oviparous reproduction, white blood, existence of heart, blood vessels and gills, liver; and externally – by mantle and tentacles”. Cuvier’s classification scheme divided molluscs into three orders: cephalopods, bivalves, and gastropods.  (from M.V. Vinarski)

Mono-: From the Greek monos meaning single, one of, alone. Hence monoclinic (crystals with a single axis of symmetry), or monotonic (never varying in pitch – or a mathematical function that always increases or decreases).

Monomict: A combination of two Greek word elements, miktos meaning mixed or mingled, and monos meaning one or single. The term was coined by Finnish geologist Walter Wahl (1952) to describing coarse grained meteorites (breccias) composed of a single kind of clast. He also coined the term polymict.

Mons: From the Latin mons which is singular for mountain; plural is montes. Not commonly used for terrestrial names, but in common use for planetary mountains – e.g., Olympus mons (Mars’ largest shield volcano).

Moon: This word is rooted in many ancient languages in the definition and measurement of a month, as a lunar month. From Proto-Indo European menses meaning month as a measure of time, thence proto-German menon-, Old English mona, and Middle English mone, and Greek mene for moon and men for month. Galileo (1564 – 1642) was one of the first to extend the meaning to moons of other planets, particularly Jupiter.

Moraine: Ultimately from the vulgar Latin murrum, meaning mound, to an Italian dialect morena meaning more specifically a mound of earth; initially not having a glaciogenic connotation. The French word for this was moraine. It’s use as a term for glacial deposits consisting of an unstructured mix of clay through boulder sized material was published by Horace Bénédict de Saussure in 1779, although it did appear in an unpublished manuscript in 1764. Saussure also introduced the term roches moutonnées (Carozzi, 1996, Journal of Geoscience Education.

More: (adj) From the Proto-German maiz and Old Saxon mera meaning greater, stronger, to Old English mara, transforming to mo in Middle English or the adverbial form ma, as in euermo (evermore) then more later in Middle English, and mare meaning greater. Middle English also used the expression lasse and more (less and more).

More or less: A common expression that reverses the Middle English version lasse and more, or ‘less and more’.

Mountain: From the Latin noun mons, from which the adjective montaneus gives us mountainous, and Old French montaigne. There may be a connection with Old English munt. The modern word has Middle English connections in mountein and montaine.

Mud: From the Proto-German word element mud- to Old German mudde, and adopted in Middle English in the 14^th C where it had several meanings – as in clay, excrement, marsh, possibly linked to the Greek mydos meaning damp. Middle English also used fen and laire for these same or similar meanings. Other Middle English spellings were moode, mudde, and the modern version mud. The Middle English adjective was mudly meaning muddy. The physical sense of mud as a cohesive, sticky slurry was in mentioned in ancient Greek dialogues on natural causes. James Hutton and Charles Lyell make frequent reference to it in the context of sediment where it is distinguished from coarser materials (sand, gravel). The formal definition in relation to particle size is detailed in the Udden-Wentworth grain size scale (1922).

Multi-: A common word element (prefix) derived from Classical Latin multus meaning much, many, or great. In Middle English it was used as a verb, for example multiplye (meaning multiply), and participle multiplicacioun (multiplying). I have not found reference to it in Old English.

N.B.  An abbreviation from the 18^th C Latin nota bene, meaning “take note” or “be aware of”. It is capitalized and each letter is followed by a period.

Nature: From the Latin natus meaning born and natura that refers to qualities in the world, the sky. Thence to Old French nature meaning the essence of things in the physical world. Chaucer’s Middle English reflects this in the Knight’s Tale (1387–1400) “Nature hath now no dominacioun. And certeinly, ther Nature wol nat wirche,” (“Nature has no domination/vigour there; And certainly, where Nature will not work,”). Galileo uses the Italian natura to describe physical attributes, but also in the figurative sense of the nature of things. Newton uses the Latin Naturalis in the title to his Principia (1687). The expression nature versus nurture was coined by Francis Galton in the mid-1800s, an English statistician (and cousin to Charles Darwin) in an analysis of human intellect. But the juxtaposition of nature / nurture has been around since the 16^th C; Shakespeare (1564-1616) makes reference to these qualities in some of his plays (e.g., The Tempest); one theme explores the difference between siblings Miranda and Caliban, separated at birth – Miranda is a picture of innocence, natural, whereas her brother tends towards savagery.

Negative: From Latin negativus (adjective) meaning denial, saying no, to Old French negatif and Middle English negatif. A negative attitude is probably 19^th C. Negative in the context of arithmetic subtraction is attributed to Indian mathematician Brahmagupta in the 7^th C – he also outlined the rules for addition. The definition of positive and negative electricity is attributed Benjamin Franklin (1706-1790), in 1747. Negative ions (an atom with more electrons than protons) were discovered by Philipp Eduard Anton Lenard during his experiments on cathode rays (1888-1903). 

Neo- From the Greek neos, and later old English meaning new, young, youthful. Examples: Neogene (the youngest period in what used to be called Tertiary); neotony (juvenile characteristics of a species retained in adults); Neoproterozoic (the youngest Era of the P.recambrian).

Neptunism: The theory introduced by Abraham Werner in the late 18^th to explain all forms of crystallization in Earth rocks by precipitation from primitive oceans; this included igneous rocks (G. Seddon, 2007).  Layering of crystallized rock was formed by the recession of the seas from land. The theory also aligned with theological views of creation (making use of the Noachian deluge). Werner also recognized that some rocks were more “primitive”, and some rocks harder than others and within this theoretical framework he erected a general time stratigraphy that had the oldest remnants of Earth as Primitive, followed by hard rocks (including fossiliferous rocks) that he named “Secondary”, softer semi-consolidated rock was “Tertiary”, and unconsolidated, recent alluvium “Quaternary”. These stratigraphic designations lasted well into the 19^th C. The name is derived from Neptune, the Roman God of the sea.

Neutron: Coined either by William Harkins or Ernest Rutherford in 1921 for the neutral particle in the atomic nucleus, from the old Latin neutralis meaning neither one thing nor the other. The term was coined about the same time as proton by Rutherford in 1921.

Nevertheless: The combination of Middle English adverb neuere and the Middle English adjective lesse and verb lessin meaning to diminish, to neuer (nevertheless). Additional Middle English combinations include neuremore (nevermore), and neuer the neer (none the nearer).

Nitrogen: The 7^th element on the periodic table (Atomic weight 7) was discovered by English chemist Daniel Rutherford in1772 by removing oxygen and carbon dioxide from air (then tested the remaining gas on an unsuspecting mouse). Rutherford called it phlogisticated air. The name nitrogen was coined by French chemist Jean Chaptal (1756-1832) in 1794, from French nitrogène, that is derived from the Greek nitron or nitre (sodium carbonate), -gen meaning giving birth to.

Noise: (noun) Noise has an interesting etymology. On the one hand it is thought to derive from the Old French noise meaning a quarrel, loud sounds including from musical instruments, a brawl, rowdy. The alternative origin is from the Latin nausea meaning disgust, annoying, and also the noise associated with sickness. The alternative Latin root is noxia meaning to hurt, or hurtful (as in obnoxious). The context of electrical noise is probably the end of the 19^th C, and signal-to-noise ratio the early 1920s (e.g., (Arnold, H.D.; Espenschied, Lloyd, 1923, Transatlantic Radio Telephony. Bell System Technical Journal, 2: 4. October 1923 pp 116-144). Einstein is often credited with formalizing concepts of noise, including statistical noise in 1905. However, rather than seeing noise as something to be avoided, he determined that it can form the basis of new ideas and discoveries (e.g., Leon Cohen, 2005, The History of Noise.

Nomenclature: (noun) From the Latin nomenclatura meaning the calling of names, from the word elements nomen meaning name, and calator or calare meaning call. The English spelling is from later French nomenclature. The concept of nomenclatural structures in science was certainly developed by the late 18^th C, as in Lavoisier’s Traité Élementaire de Chimie (1789) “L’impossibilité d’isoler la Nomenclature de la science & la science de la Nomenclature, tient à ce que toute science physique est nécessairement formée de trois choses:” – “The impossibility of isolating Nomenclature from science and science from Nomenclature, is due to the fact that all physical science is necessarily formed of three things:”

North: From proto-German nurtha- to old English nord meaning north direction. Words in old Norse, Dutch, Saxon and modern German are very similar and have the same root. Links to Nordic – Scandinavian language and people, also referred to as Nord in Beowulf, an Anglo-Saxon poem for which the surviving manuscript fragments are about 1000 CE, but the composition may have been written before that time. Maps with north at the top became the norm in 16^th C Europe, in part because of European expansion, colonization, and the developing Eurocentric view. The first major north-up map was produced by Flemish cartographer Gerardus Mercator in 1569.

Notwithstanding: Probably a Latin root from non obstante meaning not standing in the way, to the Middle English present participle of the verb standen or stonden meaning to stand, and the verb at-stonden meaning to withstand or to stop.

Number: In the context of counting and arithmetic, both noun and verb from Latin numerus meaning a quantity, thence Old French nombre. Earliest use of the verb form is 1325 (OED) in the Chronicle of Robert of Gloucester although in Middle English (1150-1580) the French noun nombre and variation on the verb nombren were also used (Mayhew and Skeat, 1888). Chaucer makes frequent use of these word in his Canterbury Tales (1387–1400). Although the use of numbers in counting systems, for example tally marks, probably dates to very early human societies; the oldest known number notations and symbols are Mesopotamian (5000-6000 years ago). However, the actual use of number words like one and two dates to Old English and Old French (pre-1150).  The sophisticated use of numbers in Arithmetic was as early as the 3^rd or 4^th century Bakhshali manuscript. The first definition of zero as an actual number was made in 628 CE by Hindu astronomer and mathematician Brahmagupta. Leonardo of Pisa (a.k.a. Fibonacci) introduced Arabic numerals to western culture in 1202, including the ‘0’ notation. 

Obliquity: From Latin obliquus meaning slanting, or indirect; the prefix ob- means facing or against. Middle English used oblike along with the modern spelling oblique, Old French obliquité. Obliquity in an astronomical sense refers to the difference between tilt of the rotation axis and orbital axis (it can also be measured relative to the celestial equator). Earth’s current obliquity is about 23.4^o.  It gives rise to the summer and winter solstices. The earliest measurement of Earth’s tilt is by the Greeks about 350 BCE. Western science refined these measurements, beginning in the early 16^th C (e.g. Tycho Brahe). Popularisation of periodic changes in obliquity as one of the orbital cycles that can influence solar insolation followed the work of mathematician Milutin Milankovitch (1879-1958), published in 1941 (commonly referred to as Milankovitch Cycles).

Obsidian: Volcanic glass, possibly named by Pliny after some Roman dude named Obsius, using the Latin Obsianus meaning dark, or black, and obsianus lapis meaning black stone. The addition of a ‘d’ in obsidian appears to have been some historical misprint. Its presence in volcanic terranes was well known by the 18^th and 19^th C, as in Lyell’s Glossary (in the Principles, 1830-1833) – “A volcanic product, or species of lava, very like common green bottle-glass, which is almost black in large masses, but semi-transparent in thin slices. Pumice stone is obsidian in a frothy state…” p. 452, Lyell 1837). The OED has the earliest use of the misspelled obsidian as 1601.

Ocean: From Greek ōkeanos, thence to Latin oceanus, and French ocean, prior to 16^th C referred to the body of water thought to surround the Eurasia-Africa landmass. The term and concept expanded with ocean exploration. Biblical reference in the Old Testament was to ‘seas’ rather than ocean. The Middle English spelling was occean.  I could find only a single entry for ‘ocean’ in Chaucer’s Canterbury Tales (late 14^th C). However, Rabelais’ Gargantua and Panteguel (1534) makes several references, thus “I will not launch my little skiff any further into the wide ocean of this dispute,…” (Chapter 3, XXXII). Christopher Columbus’ (1451-1506) official title was “Admiral of the Ocean Sea“.

Oceanography: A term coined by Sir John Murray (1841-1914). Murray wrote in an essay on The State of Ocean Science in 1899 that The recognition of oceanography as a distinct branch of science may be said to date from the commencement of the Challenger investigations.   He was a key player and contributor on the Expedition 1872-1876, one of the first expeditions to examine scientifically all the major ocean tracts. In the Introduction to Volume 1 (1895) – Report on the scientific results of the voyage of H.M.S. Challenger during the years 1872-1876, there is an account of The Science of Oceanography. On page 1, there is the statement “All this vast assemblage of knowledge, which embraces some aspects of astronomy, geography, geology, physics, chemistry, and the biological sciences, makes up the modern science of oceanography.”

Octa-: Word element From the Greek okta- and okt– meaning eight, and the Latin octo-. As in octahedral, octahedron.

-oid: Latin suffix from Greek eidos meaning form, or like something. As in spheroid, ellipsoid, colloid, but v-oid (void) is a lack of form or substance.

Old: The word has ancient roots, probably back to PIE. From ancient German ald and aldaz, to Old English ald and eald meaning ancient or aged (eald, ealdum occur frequently in Beowulf – 700-1000 CE), to Middle English olde, as in ye olde professor. In common use as a stratigraphic indicator (older, younger) since the 16^th C (da Vinci, Nicholas Steno, Lavoisier). It is the essence of Steno’s principles of stratigraphic succession (1669).

-ology:  From Latin …logia and French …logie, meaning, of knowledge, the study of things such as science. As in Etymology – the study of the origin of words; Geology – the study of the Earth and Earth history.

-ome: The suffix from the Greek for all, every, or complete. As in genome, biome

One: From Old German, thence Old English an, and later German ein (noun, pronoun, or adjective) meaning singular, and individual, sometimes spelled won.

Ontology: The metaphysical study of knowledge or being, from Latin ontologia. Thus, pale-ontology relates to knowledge of ancient life and ecosystems.

Op. cit.  An alternative to ibid, from Latin opere citato meaning “in the work cited.” Example: Prime Minister N. Chamberlin’s address to the nation and parliament in 1939 (op. cit.) carried the voice of a disillusioned man.

Orbit: From Medieval Latin orbita meaning wheel track or path. Earliest use as a description of the eye socket. Astronomical use derives from the word element orb meaning globe, spherical body, or heavenly body. Francis Bacon refers to planetary orbits in his 1620 Novum Organum.  Later, Isaac Newton’s usage of orbita and the plural orbitae were central to his theory of gravity (Philosophiæ Naturalis Principia Mathematica, 1687).

Organic: Has several different meanings through history – As an instrument Middle Ages), from Latin organum, originally from Greek organikos and Latin organicus, in anatomy and biology (15^th C), associated with life (18^th – 19^th C), a system composed of parts (19^th C), organic chemistry (19^th C – a term first used in 1807 by Swedish chemist Jöns Jacob Berzelius to distinguish compounds based on carbon), and derived from living matter (e.g. compost) (19^th – 20^th C).

Organize: From Greek organon and Latin organum meaning instrument or tool, as in Middle Ages musical instruments, and later specifically referring to a pipe organ. Organum is associated with Middle Ages Gregorian chants in the context of a collection of voices (mainly 9^th and 10^th C). The word organum was also used in texts in the context of organized ideas, philosophies, and sacred texts. Francis Bacon’s Novum organum (1620) is a treatise on the value of nature and the relationship of Man to the external world.

Orient: (noun) From the Latin orientem (oriens) meaning from the east, as in the rising of the Sun. To Old French orient, thence Middle English. The verb form probably originated later, as in orienting oneself. The magnetic compass, although originally used in China almost 2000 years ago for religious purposes, later became the primary instrument to find direction – to orient. Orientation (adjective) is an important measure in science.

Orogeny: From ancient Greek oros meaning mountain and genesis meaning origin or creation. The French derivation orogénie was used in the 1880s to mean mountain building (also its modern meaning), and introduced to American geology by G.K.Gilbert in the Lake Bonneville U.S.G.S. Monograph, 1890.

-ous: A word ending that creates adjectives from the associated noun, meaning having, having to do with, doing. From old French -ous or -eux. Examples: Ferrous (having to do with Iron Fe in a reduced 2+ state), mountainous (having the form of a mountain).

Outcrop: Derived from the word crop in the sense of head or sprout – rock exposed at the top of the Earth. In common use in 19^th C (e.g., Lyell, Darwin, Johannes Walther) The German equivalent – aufschluss (e.g., Johannes Walther); French – l’affleurement (e.g., Lavoisier).

Oxygen: Named by Antoine Lavoisier in 1777 although co-discovered by Jospeh Priestly in 1774, who called it dephlogisticated air, and Carl Scheele in 1773. The name includes a Greek prefix oxys meaning sharp (tasting) or acid, and genes meaning formation or creation of (hence genesis), and French –gène. Lavoisier discusses the burning of coal-carbon in oxygène in his Traité élémentaire de Chimie, (Elements of Chemistry, 1879), Chapter 5.

Pacific Ocean: Given the Latin name Mare Pacificum Ferdinand Magellan in 1520, meaning “peaceful sea”.  Perhaps the Pacific seemed peaceful after enduring the maelstroms of the Straits of Magellan (southern Chile).

Paleo…  The latinized form of the Greek palaios meaning old, ancient, primitive.             Example: Paleontology – the study of ancient life forms; paleoclimate.

Paleo- vs palaeo-: Both word elements are from the Greek palaios. The English version replaced the ‘i’ with ‘e’, as in palaeobiology, with the American variant paleobiology. The English version is sometimes written with the diagraph ‘ӕ’.

Pangaea: The name of a Paleozoic supercontinent coined by Alfred Wegener in his The Origin of Continents and Oceans (1915). The name derives from the Greek Pangaia meaning, where pan means all, and -gaia means Earth. His map reconstruction is presented in Figure 23, in his 1920 paper on the topic.

Pass: (verb) From Latin passus meaning to step away, and Old English passen meaning to go to one side. The past participle is passed from which the variant past is derived.

Past: (adjective) A variation of passed, from Old English verb passen and Old French passer, meaning having gone by. This and the noun form, as in referring to the past as an older event, are 13^th C.

Pebble: From the Old English papolstan meaning pebblestone, a rounded stone smaller than a cobble. The Old English stan and Middle English stane mean stone. As a defined grain size look to Udden (1914) and Wentworth (1922).

Pen… as in penultimate, penumbra, from the Latin paene meaning almost. Thus, penultimate is the next or second to last, and penumbra is the partial shadow region outside or next to the region of full shadow.

Peri…  Of Greek origin, used in words that describe around, through. Examples: perimeter (an outside boundary); pericratonic (outside or bordering a craton).

Period – full stop (.): This was first used as a punctuation mark by Aristophanes (446-386 BCE) – it had been used as a numbering system place holder since about 2000 BCE. It became a common punctuation embellishment by the 6^th – 8^th centuries, appearing in many biblical texts. In its early use, Isidore of Seville (7^th C) arranged periods to denote different kinds of pause – short (.), medium (·) and long (^·). The short (.) pause is now replaced with a comma; the period now indicates the end of a sentence.

Period, period (stratigraphic): In Middle English to denote something that has run its course of time, such as a life span, or a disease, and medieval Latin periodus meaning a cycle or recurring event. In stratigraphy, used informally until the end of the 19^th C (not capitalized) to describe almost any span of time represented by rocks and fossils, whereupon it became a more formal designation for the subdivision of Eras, such as Middle Cambrian (that is now an Epoch), and intervals like the Triassic (e.g., Dana, 1905). Today, the Cambrian in its entirety is a Period, as is the Triassic.

Perma-: Word element from the Latin permanere meaning something that remains or is permanent. Hence permafrost, permaculture.

Permafrost: From the Greek word element perma– meaning permanent or remaining, and frost. Shortened to permafrost, a term introduced by Siemon Muller in the early 1940s. Muller was also an expert paleontologist, stratigrapher, and structural geologist (Geological Society of America).

Petro- From the ancient Greek petros meaning stone, rock, cobble, etc. and later the Latin petra. From which we get petrography – probably early 19^th C, meaning the description of rocks (see -graphy), whereas petrology is the study of rocks in order to understand their origins. From the early 20^th C petro- morphed into words like petroleum and petrochemical.

pH: Introduced by Søren Sørensen in 1909 as a descriptive scale for acidity. It is expressed as the negative log₁₀ of the hydrogen ion concentration: The scale ranges from 0 to 14, with acids 0 – 7 and bases 7-14. A pH of 7 is regarded as neutral.  It continues to be the standard expression for acid-base chemistry.

Photo: As a prefix, from the Greek photo, photos meaning light. Hence photosynthesis, photic zone, photochemical. As a stand-alone word, photo it is a shortened form of photograph coined in 1839 by Sir John Herschel (son of the famous astronomer), at the cusp of modern photography.

Phylo…  From the Greek phylon meaning a tribe or clan. From which we get phylum, and Phylogeny (the unravelling of evolution in terms of descendants and relations).

Phylum: (plural phyla) The term for a major group of animals and plants, coined by Georges Cuvier in his classic Le Régne Animal  (1817), from the Greek phylon meaning a tribe or clan. The link takes you to a readable version – in French.

Π (pi): Pi is the 16^th letter of the Greek alphabet. As a mathematical constant it represents the ratio of the circumference to diameter of a circle. One of the earliest records of its use as a constant is from a Babylonian papyrus dated 1900–1600 BCE. The word derives from the first letter of the Greek word for circumference – περιφέρεια. Different values for Π were used in formulae to calculate the area of a circle, ranging from 3 to 3.1605. Archimedes of Syracuse (287–212 BCE) used Pythagorus’ Theorem to calculate a value between 3.1429 and 3.1408. Indian mathematician Aryabhata (5^th C CE) calculated a value of 3.1416 that he used in astronomical calculations and is very close to the modern value 3.14159 (History Today). The symbol was first introduced to Western Europe by William Oughtred (c. 1575-1 660), in Clavis Mathematicae (1631) but he used it as a variable number rather than a constant. It modern use as a constant was introduced in 1706 by Welsh mathematician William Jones in Synopsis Palmariorum Matheseos (A New Introduction to the Mathematics),  and popularized by Leonhard Euler in 1737.

Planet: From Greek planētēs, and planētai, commonly applied to wandering stars. Later in Old English (planete) and Old French planete as astronomical terms to stars that were not fixed. The meaning of a celestial body that orbits a star derives from the revolutionary cosmologies of Copernicus (1473-1543) and Galileo (1564 – 1642) who placed the sun, rather than Earth at the centre of the known universe.

Pleistocene: From the Greek pleistos meaning much or more, and the word element -cene meaning recent – the most recent geological period. The name was introduced by Charles Lyell in 1839 to describe the shelly fauna in Sicily that includes modern species; he initially referred to the interval as Newer Pliocene. It extends from 2.58 – 0.0017 Ma and includes several major glaciations. It is preceded by the Pliocene. It is also the period when Homo sapiens evolved.

Pliocene: Initially defined by Lyell in 1833, with two divisions – the Older and Newer Pliocene – the Newer is now the Pleistocene. Hence its etymology is similar to that of Pleistocene – from the Greek pleistos meaning much or more, and the word element -cene meaning recent. The Latin form of -cene is recens from which we also get recent. The Pliocene spans 5.333 – 2.58 Ma. It is the ultimate Series in the Neogene System.

Plume: Seems to have had multiple origins and meanings. The most common is associated with feathers (noun), from Latin pluma, thence Old English plum and Old French plume. Hence plumage (e.g., Chaucer, ~1370). However, the word plum was also used for the fruit in Old English. According to the OED, the earliest verb form is from John Metham 1449, a Middle English writer and poet, although this form is less frequently used. The characteristic structure of feather plumes has been adopted to describe smoke, subaerial dust and volcanic ash, and sediment-water mixtures, particularly mud plumes. I could find no reference to the sedimentary context in Hutton or Lyell.

Poly-: A word element (prefix) from the Greek polys meaning much or many. It is grammatically correct to use the prefix only with other Greek derivatives, as in polymer, polygenetic, polymorphism.

Polymict: A combination of two Greek word elements, miktos meaning mixed or mingled, and polys meaning many. The term was coined by Finnish geologist Walter Wahl (1952) to describing coarse grained meteorites (breccias) composed of several different clast types. He also coined the term monomict.

Poro-: From Latin porus and Greek poros meaning a small hole or opening. As in porous, porosity.

Porosity: From the Latin and Greek roots for poro-, thence medieval Latin porositas and Old French porosité. Its adjective form porous was in common use 15^th and 16^th C. Nicolas Steno (1669) refers to poros – “confpicuam ibi di- diuerfitatem obferuandam fuifie inter ftrati mate¬ riam , & materiam per ftrati poros…” – “a significant difference should be offered there between the material of the soil and the material through the pores of the soil.” that is an indirect reference to porosity in natural deposits. There are multiple references to porous in James Hutton’s Theory of the Earth (1795) and several of Charles Lyell’s volumes from 1830 on, but the first reference to porosity that I could find in Lyell is in his Manual of Elementary Geology, 6^th Edition 1858, “As to the absence of porosity in the trappean formations, the appearances are in a great degree deceptive…” in reference to amygdaloids in basalts.

Positive: From Latin positivus and Old French positif.  Earliest meaning is related to legal matters, as in settled by agreement (13^th -14^th C). There are multiple subsquent meanings, such as positive identification, and positive thinking (the latter is probably 20^th C). The mathematical context, as in greater than zero is usually attributed to Indian mathematician Brahmagupta in the 7^th C – he also outlined the rules for addition, subtraction (negative). The definition of positive and negative electricity is attributed to Benjamin Franklin (1706-1790), probably around 1747, although the notion of electrical charges is probably from Charles Augustine de Coulomb (1736–1806).

Potash: English probably from Old Dutch (to about the 12^th C) potaschen, meaning the ashes from a pot. OED has the earliest use in English from early 16^th C. The word also gave rise to the chemical symbol for potassium (K) derived from the Latin Kalium.

Potassium: From the Old English word potash that itself derived from pot ashes, that in Latin is kalium from whence the symbol K is derived. It has been known for centuries that potash (potassium hydroxide – KOH) can be made by soaking wood ash in water. It is an important ingredient in soap that also was discovered in firepits where leached potash reacted with animal fats. The element potassium was discovered by Humphrey Davies in 1807.

Pratt isostasy: Named after John H. Pratt  who, in 1855 proposed a model to explain gravity anomalies, whereby all crustal blocks (that float on the mantle) have different densities, different elevations above a datum, but the blocks terminate at the same depth below the datum – this is the depth of compensation (cf. the Airy model).

Precession: From Latin praecissionem meaning something that goes before or precedes. It originated from the astronomical calculation of the equinoxes. Actual discovery of the equinoxes is commonly attributed to the Greek astronomer Hipparchus (c. 190–120 BC), although the Latin term didn’t appear until the 16^th C. It refers to the periodic or cyclic wobbling of Earth’s rotational axis. Popularisation of precession as one of the orbital cycles that can influence solar insolation followed the work of mathematician Milutin Milankovitch (1879-1958), published in 1941 (commonly referred to as Milankovitch Cycles).

Present: (adjective) From the Latin verb praesent, and past participle praeesse, meaning instant, a time, to Old French present and Middle English. The verb form is a variation from the Latin praesentare and Old French presenter. The meaning as in now, or this time from a geological perspective was central to James Hutton’s Theory of the Earth (1795), and the oft-quoted phrase “the present is key to the past” is attributed to Charles Lyell (1830). But this meaning had been in use for at least the previous 200-300 years, for example in Francis Bacon’s Novum Organum (1620).

Preservation: From 13^th C Latin preservationem and old French, meaning protection or guard. The Medieval use of preservacioun meant protection from disease. Antoine Lavoisier used preserve in the context of a body’s condition at different depths of burial. The geological contexts of physical state (e.g., of a fossil), or taking care or, or conservation of, was a familiar usage at least at the beginning of the 19^th C (e.g., Henry De la Beche, 1824).

Prism: From ancient Greek prisma then Latin prisma, apparently originating with Euclid who gave it the geometrical meaning of a solid with parallel parallelogram sides (literally it means ‘sawn off’). The first documented use in English is from the 1570 translation (from the original Greek) of Euclid’s geometry, by Henry Billingsly (Elements of Geometrie). In optics, prisms were used to study refracted light and spectra, most famously by Isaac Newton in 1704, in his book Opticks: or, A Treatise of the Reflexions, Refractions, Inflexions and Colours of Light. The word has been borrowed to describe crystal forms consisting of parallel faces (usually parallel to the c-axis). The more recent use of the word in phrases like ‘tidal prism’ are rather loose adaptations of its meaning. Francis Bacon (1620) uses prism in the context of colours emitted from a crystal and reflected off a surface. Abraham Gottlob Werner (1749-1817), a German mineralogist, describes the basic crystals forms such as cubes, pyramids, and prisms as four parallel-sides in Von den äusserlichen Kennzeichen der Fossilien (Treatise on the exterior characters of fossils – 1774), for example p. 164.

Probability: From the Latin probabilism and probabilitatem meaning credibility, and Old French probabilite. I have not found a Middle English form, but the word liklinesse or lyklinesse also meant probable. It appears later in the 15^th C with the same spelling as the French – probabilite, meaning the appearance of truth, likelihood, or approvable. The mathematical treatment began with Italian Gerolamo Cardano with introduction into scientific thought by Pierre de Fermat, Blaise Pascal (1654) and Christiaan Huygens (1657), based in part on the principles of games of chance. In the 2^nd Edition of The Celestial Worlds Discover’d, Huygens (1722) notes “In ſuch noble and ſublime Studies as theſe, ’tis a Glory to arrive at Probability, and the Search it ſelf rewards the Pains. But there are many degrees of Probable, ſome nearer Truth than others, in the determining of which lies the chief exerciſe of our Judgment.” where probability can be thought of as being closer or less close to the truth.

Process (noun): From the Latin processus meaning to advance, or progress, thence 14^th C Old French proces meaning a journey, or legal position in a trial. The modern meaning of a series of events or actions that lead to some result is 17^th C, as is commonly expressed in 20^th and 21^st C geological models as process-response.

Process (verb): as in to process some event or action, to investigate, is 15^th C from French processer. Due process as in law is also 15^th C.

Process-response: Commonly used compound term to describe geological models, where certain processes lead to predicted or observed responses – i.e. cause and effect. The earliest reference I have found to this is E.H.T. Whiitten, 1964 Process Response models in geology although L. Sloss, 1962 refers to process models and response models in his SEPM paper Stratigraphic models in exploration.

Proof: From the Latin noun proba and the verb from probare, and Old French preove meaning evidence, truth, facts, and Middle English preove (12^th-13^th C) The ‘v’ was transformed to ‘f’ when the last ‘e’ in preove was removed. Other Middle English verb forms included prouen, preouen, pruf, and the Middle English noun proue. Chaucer used the past participle proved in his Prologue to Canterbury Tales (1392) “That proved wel, for over-al ther he cam,” The long vowel sound of ‘eo’ and ‘ou’ in Middle English appears to have changed to the digraph ‘oo’ somewhere from 1350-1700.

Proto/Prot-  A prefix of Greek derivation, from proto and protos meaning first or before. As in Protoplanet, protein, proton.

Protero-  From Greek proteros meaning before, earlier. Example: Proterozoic – the geological era before modern life.

Proton: Coined by Earnest Rutherford in honour of the early 19^th C scientist scientist William Prout, based on experiments on atomic nuclei, from the Greek protos meaning first. It seems Rutherford wanted the term Prouton, but settled on the name we use now.

Proxy: From old Latin procuratia and 13^th C French procuratia to Middle English, meaning administration, or substitute authority.

Pumice: From the Latin spuma meaning foam with the rock name spuma lapis meaning froth of the sea, morphing into a vernacular Latin pumex or pomex for the rock. Pliny the Younger used similar terms that translate from Latin as pumice stones, in a letter to Tacitus, probably after 79 CE.  The name entered Old English as pumic, and pumicstan for pumice stone, and Middle English as pumish and pumey. One Latin text dated 1425, The Medulla Grammatice, a 15^th  C Latin-English glossary, has an entry for (Latin) pumex and Middle English pomeys ston.  The name pumice stone carried into the 18^th and 19^th C – it is mentioned in Charles Lyell’s Principles (1^st Ed. 1830-1833).

Pycnal: Ancient Greek puknos, meaning dense, compact, or thick. Examples: pycnocline, hyperpycnal flow

Pyramid: From the Greek pyramis (singular) and pyramdies (plural), to Latin pyramides that referenced the Greek Pyramids. Old French pyramide and Middle English piram also referred to solid forms with a polygonal base and sides meeting at a point, as in a pyramid or obelisk. The OED has the earliest use in English as before 1398. Francis Bacon (1620) describes flames in this geometrical sense “All flame, therefore, is pyramidal, having its base near the source, and its vertex pointed…” One of the earliest descriptions of pyramidal forms in crystallography is Abraham Gottlob Werner (1749-1817) in 1774,  ,p. 164 “La pyramide est la figure primitive d’une crystallisation composé d’un nombre intéterminé de plans triangulaires, qui, par leur inclinaison, vont se réunir en pointe **;” (The pyramid is the primitive figure of a crystallization composed of an indeterminate number of triangular planes, which, by their inclination, will meet at a point – 1795 translation from German to French).

Pyro-: A prefix from the Greek pyr meaning fire, commonly associated with raging blazes as in forest fires or the fires of Hell, funeral pyres, and lava flows as molten rivers of fire. Probably from a PIE root paewr. Hence pyroclastic, pyrotechnic (fireworks), pyromaniac, and pyrolysis.

Pyroclastic: Literally, clasts derived from fire. Apparently the first use of the word in its volcanological meaning was by J. Beete Jukes in ‘The Student’s Manual of Geology’, 1862 (Edinburgh).

Quad-: A Latin prefix or root form meaning four or forth. Examples: Quadrant, quadratic, quadrupole.

Qualitative: (adj). Has a similar etymology as quantitative, with Medieval Latin stem root qualitas meaning quality (noun) and its adjective qualitativus meaning having a relationship with variables like volume, density etc, but not quantities.

Quantitative: (adj.) From the stem noun quantity that has its roots in Medieval Latin quantitatem, thence Old French quantite meaning having magnitude, amount, or extent. The noun was in common use in 16^th – 17^th C scientific dialogues (Steno, Galileo, Newton) and commonly referred to measurable quantities. The derivative adjective is also from old Latin quantitativus. Apparently appears in the mid 17^th C, but I have not found any reference to the adjectival form in any geological context before Archibald Geikie’sText book of Geology, 1882, p.193 with reference to analysis of powdered rock (he also refers to qualitative analysis in this section), that he has probably borrowed from chemistry. Although quantitative analysis has been around for centuries in the form of measurement and counting, its formal usage is more recent. For example, Lavoisier (1788) created a more formal use of quantity and quality in chemistry, as in quantitative analysis, although even he did not use the adjective form.

Quartz: Thought to have been derived originally from Slavic tvrdy or Polish twardy to German twarc, from which Middle High German Quarz, meaning rock crystal. One of the earliest mineralogical uses is by Agricola Georgius (real name Georg Bauer) in his De Re Metallica, 1556.

Re-: A common word element originally from the Latin re- and Old French, meaning back or again. There is some debate whether it entered Latin from older PIE wret-, wert-, or ure-. In Middle English it was common to add the prefix to almost any word. In the sense of ‘back’ or ‘again’ words like relocate and redirect are common. But it also is a prefix for words where the original meaning is less clear, as in religion, or receive. An Older Latin variation was red- as in redundant where undant is a parsed form of the Latin verb undō meaning to wash.

Regolith: Both prefix and suffix are from ancient Greek – rhegos meaning blanket or overlying layer, and lithos meaning rock or stone. The term was introduced by G.P. Merrill in 1897 in A Treatise on Rocks, Rock-weathering, and Soils. In the 1913 edition of this volume, Merrill elaborates on the term in PART IV – The Regolith (p. 287), applying it to “This entire mantle of unconsolidated material, whatever its nature or origin, it is proposed to call the Regolith,…”.

Reynolds number: Named after Osborne Reynolds (1842-1912) for experiments in glass pipes that determined the bulk structure of fluid flow, in particular the transition from laminar to turbulent flow. The results were published in 1883.

Rheo-: From the Greek rheos meaning flowing or current. Examples: rheostat, rheology.

Rheology: The name was proposed on April 29, 1929, by E.C. Bingham and M. Reiner, at the inauguration of the Society of Rheology. They defined it as “the study of the flow and deformation of all forms of matter”.  There is a brief history of the name and the Society by D. Doraiswamy. Formed from the Greek word elements rheo meaning flowing and -ology that pertains to knowledge and the study of things. 

Ripple: The verb form, to ruffle a surface and as small waves probably from 14^th C riplen. The OED indicates the earliest reference to the verb form is 1350. DaVinci makes several references to the surface form in his discourses on water and hydraulics. The noun form from this somewhat later. The use as a bedform in geology and geomorphology seems to have become more common in the 19^th C – Lyell describes the formation of ‘ripple marks’ on a recent beach and as ancient bedforms in his Principles of Geology (at least in the 1872 11^th Edition), and slightly earlier in his Elements of Geology (1868), but I could not find reference to ripples in his earliest volumes. Nor in Playfair’s account of James Hutton (1802).

River: From Latin riparia meaning river, riverbank, a shore above tidal range. Hence riparian. The English version is derived from Old French riviere, and Anglo-Normal rivere. Old English ea for river has the same linguistic origin as Latin aqua. Common in Middle English literature – e.g., Chaucer’s Canterbury Tales “The brode river somtyme wexeth dreye.” And 18^th-19^th C scientific texts.

Sample: (noun, verb) From the Latin exemplum meaning a sample and Old French essample. Middle English used saumple as a shortened form of ensaumple, although its meaning was similar to ‘example’, as in a sample or illustration of something rather than a physical specimen. The OED notes the earliest verb (participle) form is 1592. Etymonline notes the earliest noun form in the context of a small sample or specimen is 1767 but does not give a reference for this date. I cannot find use of the word in any of Charles Lyell’s or James Hutton’s works, or Geikie’s early papers (pre-1900), although the word specimen is used frequently in many 18^th and 19^th C publications.

Sand: A noun and word element for nouns and adjectives. From Proto-Germanic sandam, and Old English sand meaning fine granular material usually rock. It’s modern use in Earth science stems from a definition based on a specific size determined by J. Udden 1898, and adapted to a general grain size range for granular sediment by C. Wentworth, 1922. Hence sandstone (noun), sandy (adjective). 

-saurus: As in Stegasaurus, is from the ancient Greek sauros for lizard, latinised to saurus. Thus, Tyrannosaurus is the tyrannical lizard. Its etymology is uncertain but there are some interesting comparisons. In J.R.Tolkien’s invented Elven language, Sindarin, uses saur to mean something abominable, hence Sauron (described in the Silmarillion). However, the Greek word thesauros and later latinised version thesaurus means a treasury, or book of words.

Scale: As a noun or verb it has several meanings. One of the oldest refers to scales of fish and snakes, from Proto-German skæla meaning to divide, then Old French escale and Old English scealu meaning shell or husk. As an instrument for weighing, could be from 12^th C Norsk skal (cup) or again Proto-German skæla, and Middle English scole. As a means to determine or measure some quantity like distance, it is probably Middle English. The verb form to scale (a ladder, or rampart) is from the Latin scalae. Galileo’s proportional compass is based on arithmetic scale, but I do not know if he used the word, or its Latin equivalent in his discourses.

Science: The English version of this word appeared in the 14^th C when it had connotations of knowledge. By the 17^th C its meaning had become more specific, as systematised knowledge. For example, Galileo frequently used the Latin version scientia in his dialogues. However, its use goes much further back in time, to Greek philosophers like Aristotle who used the word scientificus as an adjective to describe knowledge that had been arrived at by pure reason and formal logic. Hence the wordscientific, scientist. The modern meaning is frequently conflated with statements about scientific method, restricting knowledge to that gained from observation, experiment, and logic. But statements of the ‘method’ usually omit reference to the human capacity for creativity, and in some philosophical circles it is creativity that drives the progression of science and discovery. See S. Ross ‘Scientist: The story of a word’ 1962 (PDF available).

Scientist: According to the Stanford Encyclopedia of Philosophy, this was a term coined by the 19^th C polymath William Whewell in the early 1800s.

Sea: From Old English/German see, and Dutch zee, although this may have referred more to lake or marsh; mare or mere were also used for both lake and sea (e.g., Windermere), and mare is used for regions of the moon that looked like lunar seas.

Sediment: From Latin sedimentum meaning sinking or settling in mid-16^th C; also French sediment. Nicholaus Steno was probably one of the first to use this word. Its use gained in popularity with scientists like Antoine Lavoisier (18^th C) and later in Lyell’s Principles of Geology (1830s and later versions). From this we get sedimentology (noun – the study of, in common use from about 1950 on), sedimentation (noun), sedimentary (adjective). Also, sediment deposited in aged red wine.

Seismic: From ancient Greek seismós meaning shaking, earthquake. The study of earthquakes as seismic events began in earnest after the 1755 Lisbon earthquake. The existence of earthquake generated seismic waves was well known in the 19^th C – Lord Rayleigh predicted one class of waves in 1885 (now known as Rayleigh waves), and in 1889 the first seismogram was produced (A. Ben-Menahem, 1995).

Shear: Verb from Old English sceran and Old German skero meaning to cut, then to Middle English sheren with the added meanings of hew, cleave, shave. One of the earliest references to shear in materials science and mechanics was by Antoine Parent (1666-1716), a French mathematician who correctly determined the stress-strain relationships in a bending beam (1713). The theory was further developed by Charles-Augustin de Coulomb in 1773 who determined the relationship between shear strength (τ), normal stress (σ), and angle of friction (ø), encapsulated in his equation τ = σ. Tan(ø) + c

Shields parameter: Albert Frank Shields (1908 – 1974), an American engineer, who determined from experiments, the shear stress required to initiate grain movement, published in 1936. The Shields diagram plots this parameter against the Reynolds Number that describes the hydraulic conditions across the grain boundary.

Sic.  From Latin sic meaning thus, but is actually a contraction of sic erat scriptum, which refers to something as written. It is usually italicized or in parentheses. It commonly denotes a direct quote or statement when something is written mistakenly or deliberately, misspelled, or grammatically in error. Be careful that your use of sic is not denigrating in some way. Example: The author wrote “The sandstone bed described in you’re (sic) thesis…”

Sidero…: From the ancient Greek sidēros meaning iron, as in siderite (Fe CO₃), siderophile elements (iron loving); also the Latin sīder- meaning star or constellation. Hence sidereal.

Σ sigma: The 18^th letter of the Greek alphabet in upper case (capital) form (lower case is σ). Its usage as a mathematical summation of numbers derives from the first letter of the Latin summa that has several meanings – summit, main point, highest rank. The Old French summe and somme carried over to Middle English somme. The notation was introduced to Western Europe mathematics by Leonhard Euler in 1755, but didn’t become accepted practice until the early 19^th C with mathematicians like Fourier (1822 – in an 1878 translation), as in “Hence, denoting the sum of the preceding series by Σ cos i (x — a)” (p. 208).

Signal: (noun) From Old French signe and Old Latin signum as in a sign or token, morphing to medieval Latin signale and Old French signal or seignal meaning a sign or mark, and more modern Latin signalis. The (adjective) context as something of note or importance is probably 17^th C. Although Stephen Gray is credited with demonstrating the transmission of electricity, he does not use the word signal; a single use of sign was in the context of no sign of… . (Philosophical Transactions of the Royal Society of London Volume 37, Issue 417, 1729). Samuel Morse, who is credited as the inventor of electrically transmitted Morse Code in 1838 (others also are credited with the discovery of electrical telegraphy), in his correspondence writes of electrical signals, as in “… the successful result of passing the electricity through twenty-five hundred miles at the rate of one signal in one and a quarter second. Since then Dr. Whitehouse has succeeded in telegraphing a message through it at the rate of a single signal in three quarters of a second.” (in a letter to his wife on subsea cables – August 1, 1857).

Silica: The compound SiO₂, named silicum by Humphrey Davy in 1808, from the Latin for flint – silex. The mineral quartz has the same chemical composition and formula.

Silicon: The element Si, discovered by Swedish chemist Jöns Jacob Berzelius in 1824, but the name silicon was applied by Scottish chemist Thomas Thomson in 1831. The name derived from Latin silex meaning flint.

Silt: (noun) Became part of late Middle English word for fine sediment associated with sea water (late 1500s) borrowed from Scandinavian variations – Old Swedish sylta meaning mud, Danish and Norwegian sylt meaning salt marsh (probably muddy). Also the Middle English sealte meaning salt, and Old English sealte meaning sea water.

Slow: From Proto-German slæwaz and Old English slaw meaning torpid, sluggish, from the Old English verb slāwian to be slow, and the adverb slāwlīce. Middle English spelling was slaw and slawe, and also the modern spelling of slow or slowe. Middle English slow was a variant of sleen, meaning slay. cf. fast was also of Proto-German roots.

Snow: A word in PIE (sniegwh) that carried through to Proto-German snaiwaz and Old German sneo, Old English snaw and derivatives like snāwgebland (snow-storm) and the adjective snāwlic (snowy). These forms also occur in old Norse (snjor) and Dutch (snee). This transformed to Middle English snou, snaw, and snow.

Sodic: An adjective that usually refers to a dominant sodium component in minerals and chemical compounds, igneous rocks, or the composition of water. First use in English apparently 1859 by Robert Mayne (Source OED).

Sodium: The elements named and isolated by chemist Humphry Davy in 1807 from soda or soda ash (sodium carbonate, Na₂CO₃). The symbol Na is originally from Greek nitron and possible Arabic natrun, and later French natron.

Soil: Verb – From 13^th C English and French soillier meaning to defile, or with religious contexts to cover in sin. As a noun – from Latin solum adopted in Middle English about the same time, meaning land or earth in which plants grow. Online Etymology notes that is may be derived from three French words – sol meaning bottom or ground; soeul or sueil meaning threshold or place (also from Latin solium meaning seat); and soil or soille meaning a muddy place.

Solar: From Old English sunlic and Latin solaris meaning sun or related to the sun. The phrase Solar System is commonly attributed to Nicolaus Copernicus in his De Revolutionibus Orbium Coelestium, Libri VI (1543)

Solstice: From Latin sol meaning sun, and stitium meaning to stand still, giving solstitium. The Old English translation of this was sunstede or sunstead, from Anglo-Saxon sunne (sun) and stede meaning place or position (later morphing to stead) but was later replaced by the Old French solstice (12^th C).

South: From Anglo-Saxon sup or sud meaning toward the south or toward the sun. Hence Dutch zuid, German suden, Spanish and French sud. Early Egyptian, Chinese and Arab maps show south at the top, possibly because in the northern hemisphere that was the direction toward the sun.

Space: From Ancient and Medieval Latin spacium and later Latin spatium meaning expanse, time, position, room (as in room to move), thence to the French espace. It is possible that the words space and place in ancient Greek and Latin have some linguistic connection. One of the earliest English usages is Chaucer (1425) as in “But natheles, whyl I have tyme and space,” (The Prologue, line 35).   Alessandro Rollino (2019) has quoted Einstein thus “Now, as to the concept of space, it seems that this was preceded by the psychologically simpler concept of place.”; that the conceptualization of the immensity of space requires some innate understanding of place. The astronomical context is probably 18^th C – Newton’s Latin version of the Principia makes regular use of spatium to refer to worldly space and astronomical space, as in “Nam tempus, spatium, locum et motum ut omnibus notissima non definio.” (For I do not define time, space, place, and motion as well known to all; Scholium II.). Compound and word element constructions in 20^th C include space race, spaceship, outer space. 

Spar: As in calcite spar, sparry calcite, fluor-spar, probably 16^th C low German spar or sper, applied to a crystal that breaks easily along smooth planes – now known as cleavage planes. It is probably derived from former meaning of spear or lance from the Old English spere and Proto German sparron – sparry minerals are spear-like. Agricola Georgius refers to fluor-spar and calc-spar (gypsum, calcite) in his De Re Metallica, 1556.

Spectrum: From the Latin noun spectrum meaning an image or an appearance, and the verb specere meaning to look at, although its original meaning in Latin was a spectre, or apparition, that the OED indicates was used as early as 1611.  First reference to colours like those produced by a prism was probably Newton in 1671, in the Philosophical Transactions 1671 (Royal Society) vol. 6., p. 3076 “Comparing the length of this coloured spectrum with its breadth,…” The OED also indicates that first use of spectrum in the context of a notional range of things was 1887, as in a spectrum of depositional environments.

Speed: A word with meanings that have changed considerably in more recent times. From Proto-German spodiz and Old English sped meaning success, wealth, good fortune, to Old Dutch spoed and Old German spuoten meaning haste or hasten. Toward the end of Old English (~1450) the meaning had morphed to quickness or swiftness. Galileo (1564-1642) is credited with defining speed in a mechanical or kinematic context as the distance travelled per unit time. He also measured speed during his experiments with moving balls. The vernacular reference to speed as a recreational drug (methamphetamine) was coined in the 1960s (although it had been in use for decades earlier).

Speleology: From the Greek spelaion meaning cave, as in speleology and the Greek suffix logia meaning study or examination of. The word is relatively modern, from the French spéléologie coined by Émile Rivière (1835-1922) in 1890 (he studied caves for their fossil record, particularly human occupation).

Sphere: An illustrious etymological phylogeny, according to ETYMOLOGEEK originally from Greek σφαῖρα to Early Latin sphaera, modified in Late Latin to sphere, then ca.842 – 1400 French sphere, that is the adopted English spelling. Commonly used to describe the ‘heavens’ in Renaissance Europe and modelled with Armillary Spheres. Derivative terms like biosphere (from Greek bios,English bio); atmosphere (Latin-French atmosphére); hydrosphere (Greek to English).

Spit: As in sandspit. The coastal geomorphology context appears to have been derived from Old English spitu or old German spiutz or spiz, meaning a pointed bar or stick for roasting. A sandspit is basically a pointy accumulation of sand that extends above the sea surface and juts from a coastal promontory, enclosing a harbour, bay or lagoon.

√ Square root: The mathematical square root operation dates back at least to Babylonian scholars (2000 BCE), and was certainly in use by ancient Greeks. The operation is also described in the 3^rd-4^th C Hindu Bahkshili manuscript. The history of the √ symbol (also called a radical symbol) is based partly on conjecture. One story maintains that the symbol was derived from the first letter of the Arab word jadhir meaning root – the calligraphic form is جذر; another that Euler claimed it to be Latin origin, as the first letter in radix (root). The earliest record of the more modern form was in 1525 by German mathematician Christoff Rudolff, but he wrote it without the vinculum – the horizontal bar at top. This was added by Rene Descartes in 1637. See this link for an illustration of the Christoff Rudolff form.

Stage: (stratigraphic) A chronostratigraphic unit that identifies a specific period of geological time between two stratigraphic rock units. Stages were originally identified by specific fossils that have well-defined ages that also have global significance. French paleontologist d’Orbigny introduced the concept in 1852.  Modern usage, adopted by the International Stratigraphic Commission also includes other time-rock attributes, such as geomagnetic intervals and dated glacial events.

Star: This word has an ancient lineage, beginning with the PIE root ster, Proto-Germanic sternan-, Old English steorra to Middle English sterre, originally indicating a point of light in the night sky. The meaning ‘to star in…’ or ‘be a star’ derives from the early astronomical context. The compound star-crossed means to be born under a malignant star, or ill fated, derives from astrology that probably began at much the same time as folk started pondering the stars.

Statistics: From the Latin statisticum and late 18^th C German statistic, concerned mainly with the needs of states, or condition of a state, community or population. It is also attributed to the Latin status, and the Greek statos meaning standard. The Italian statista was introduced in 1589 and referred data about a state; also statecraft. The mathematical foundations derived by Blaise Pascal, Pierre Fermat, and others (17^th C) were based on discussions centred on game theory. The first use of the word statistics in English is 1770 according to the OED. The more general, rigorous, modern mathematical treatment of statistics was late 19^th – early 20^th C by Karl Pearson, Francis Galton, and others (from Wikipedia).

Stochastic: From Greek stokhastikos meaning to guess or conjecture, it takes its modern meaning in probability theory – initially developed by the Russian mathematician Andrey Markov (1856 -1922) with mathematical calculus developed by the Japanese mathematician Kiyosi Ito (1925-2008).

Stokes Law: Named after George Stokes who, in 1851, published a solution to the calculation of the viscous drag forces that act on particles settling through a fluid. He demonstrated that the settling, or terminal velocity of a spherical particle occurred at the point where the drag forces equalled the particle specific weight (under non-turbulent conditions where Reynolds Number was <1).

Stone: A noun, and word element. From proto-German stainaz, and Old English stan meaning pretty-well any kind of rock or gem. The root is probably PIE stai. Hence limestone, sandstone.

Storm: From old German sturm, Norse storm, stormen, thence old and middle English storm, meaning bad weather, tempests (Biblical, Shakespeare), or attack.

Strain: Probably from the PIE root streig- thence to Greek (strangein), Old French, Old German, and Old English (streinen) meaning to tie together or compress. The use of strain to mean clarify a liquid by removal of suspended solids is apparently 14^th C. The rheological meaning, as in the deformed shape of a substance subjected to stress (forces) is much later and derived from William Rankine’s (1856) paper on elasticity of crystalline solids, where strain was defined as “…the deviation of a molecule of a solid from that condition as to volume and figure which it preserves when free from the action of external forces…”.

Strata: From late 17thC Latin strata, plural stratum meaning a layer, blanket, a layer laid down. The prefix strati… is derived from this. Nicolaus Steno (1638-1686) made frequent use of the word stratum in the explanations of his three stratigraphic principles – apparently using stratum and strata 101 times in his Prodromus(1669) ((G. Battista Vai, 2012, PDF available).  Examples: stratigraphic, stratiform, stratabound, 

Stress: From Old English stresse as a shortened form of distress meaning hardship, adversity, from old French estrece. The Latin strictus means compressed or pressured and in geology it is this form that eventually gave rise to the meaning of stress as an applied force (cf. strain). The rheological sense of the word derived from a paper on elasticity in crystalline solids by William Rankine in 1856, where he defines “the corresponding effort of the molecule to recover its free volume and figure by the word stress”. Here, “effort” implies force (Rankin also defined the word strain).

Strike: (verb) The common modern meaning to hit, or apply a forceful blow is probably 14^th C, but it evolved from Old English strican and thence Middle English striken meaning to stroke or smooth, or to make one’s way, or proceed, and it is this meaning that applies to the geological term dip and strike, where strike refers to going ahead as in the expression for a rock formation or ridge line striking west (for example). The measurement of strike of a plane or body of rock as a description of its orientation appears to have been well advanced by the mid 16^th C, for example in Georgius Agricola’s De Re Metallica in 1556, written in Latin but also published in German, discusses the orientation of veins using the German streichen.

Structure: From the Latin structura and the past participle structus meaning something built, an edifice, an arrangement or order. Geological and other scientific contexts such as the structure of crystals, geomorphic features, textural properties of sediment, and strata were well entrenched by the time James Hutton published Theory of the Earth (1795). James Hall in 1815 makes a single reference to the convolutions of beds in a modern structural geology sense – “On the shore of the sea, however, where these rocks are bare, and exposed in such a manner, that our view can embrace at once a considerable extent of the mass, the general structure becomes apparent.”  Antoine Lavoisier’s (1789) TRAITÉ ÉLÉMENTAIRE DE CHIMIE cites “Cet objet a été savamment traité par M. l’Abbé Haüy, dans plusieurs Mémoires présentés à l’Académie, & dans un Ouvrage sur la structure des cristaux.” (… Work on the structure of crystals.). Francis Bacon’s Novum Organum (1620) makes frequent note to the structure of bodies, and the more figurative sense in “… to arrange facts in the structure of a science.”

Sub-: A common prefix in English derived from Latin, with various meanings: beneath (subcutaneous), below in a spatial context (submarine), below in some condition or figurative, as in subpar, division, under.

Subside: From Latin sub- meaning under, beneath, and sidere meaning to settle, giving the Latin subsidere meaning to sink, fall, or squat. The OED has the earliest reference to subside in 1607 by playwright Ben Jonson, a contemporary of Shakespeare. James Hutton (1795) makes frequent reference to the geological context of subsidence, specifically of the sea floor, as does Lyell in his ‘Principles’ (1830-1833). The process of subsidence was central to Darwin’s hypothesis of atoll reef formation.

Substrate: Refers to a foundation, layer, boundary, over which something lies, is deposited, grows, or precipitates (e.g. chemical substrates like crystals, molecules). In geology it refers to the strata, sediment, rock, shell etc.  Also substratum. From Latin sub and strata, also sternere meaning to spread out. James Hutton uses the word substratum once in his Theory of the Earth (Chapt 4). Charles Lyell also uses substratum sparingly in his “Principles”.

Subtraction: From the Latin word elements sub meaning under, and -trahere meaning draw or pull, giving the noun subtractionem meaning drawn back or subtraction. The mathematical use of the concept of subtraction dates to early Greece. It is an important operator in the 3^rd – 4^th C Indian Bakhshilli manuscript. Its introduction as a short-cut sign to European mathematics (–) was in 1498 by Johannes Widmann in his book Behende und hübsche Rechenung auff allen Kauffmanschafft (“Nimble and neat calculation in all trades”), also known as Mercantile Arithmetic.

– (minus sign): One of the most important mathematical operators, its graphical representation of subtraction is attributed to Johannes Widmann, a 15^th C German mathematician, who also invented the + (addition) sign. Widmann’s 1498 publication was Behende und hübsche Rechenung auff allen Kauffmanschafft (“Nimble and neat calculation in all trades”), also known as Mercantile Arithmetic. Widmann did not invent the arithmetic form of substraction – that is attributed to the author of the 3^rd – 4^th C Bakhshilli (or Bakhshali) manuscript.

Sulphate (sulfate): Named by French chemist Louis-Bernard Guyton de Morveau in 1787, from the Latin sulfur and sulphatus. The word sulphat is found in the English version of Antoine Lavoisier’s Traité élémentaire de chimie (1789) by translator Robert Kerr in 1790. In Lavoisier’s original text he makes frequent reference to l’acide sulfurique (sulfuric acid), and in Chapter 17 he defines the salts of various acids: “Ainsi nous avons désigné tous les sels qui ont l’acide sulfurique pour acide, par le nom de sulfates; tous ceux qui ont l’acide phosphorique pour acide, par le nom de phosphates, & ainsi des autres.” “Thus we have designated all the salts which have sulfuric acid for acid, by the name of 185 sulfates; all those which have phosphoric acid for acid, by the name of phosphates, and so on with the others.”

Super-: As a word element, from the Latin super- meaning above, beyond, over. Word elements from Old French were written as sur- as in surmount, surfeit. Compound words like supersede, superstitious, superfluous were probably in common use by the 15^th-17^th C. James Hutton in his Theory of the Earth (1795), uses words like superfluous, but also less common forms like superincumbent in the context of strata of structures lying over some other structure. He also used superposition to describe the ordering of strata with one layer overlying another, as in “I would now ask, if in all this account of the gradation of rock from the Oural mountains to the sandy coast of the Baltic, there is to be observed any clear and distinctive mark of primitive, secondary, and tertiary, mountains, farther than as one stratum may be considered as either prior or posterior to another stratum, according to the order of superposition in which they are found.”   I also found three occasions when Charles Lyell used superposition in the context of stratigraphic ordering (1837, p 43, 84, 90).

Surface (noun): from 16^th or 17^th C French sur meaning ‘above’ or ‘on’, and face meaning appearance or countenance – the old meaning of surface was as a boundary or outer plane.  Apparently, the verb form was later 19^th C, as in surfacing. The Latin version is superficies, from which we get superficial. I could not find reference to the Latin word in Steno’s De Solido (1669), nor the English version in Playfair’s 1802 version of James Hutton’s work in reference to geological surfaces like erosion surfaces, or hiatal surface.

Surge: Noun. From the Old French (8^th – 14^th C) sourgeon and the verb form from the word element sourge- meaning to rise, swell or rise up, thence Latin surgere. Its meaning as billowing, swelling or perhaps pulsating flow of water or waves is probably Middle English. OED notes the earliest use from a 1506 text The pylgrymage of Sir Richard Guylforde to the Holy Land, A.D. 1506. A copy of the text was edited by Sir Henry Ellis in 1851 – herein surge is quoted “but that the cors of the galye shulde in lykewyse haue fallen to the rok at the next surge of the see.” (but that the course of the gale should in likewise have fallen to the rock at the next surge of the sea).

Survival of the fittest: Although this well-known phrase is based on Darwin’s theory of Natural Selection, it was coined by Herbert Spencer in his 1864 book Principles of Biology – Spencer uses the phrase several times in Volume 1. In this sense, the word “fittest” does not refer to strongest or most physically able, but to the ability to adapt to changes in environment and biological competition. Darwin did use the phrase in later publications (but not his 1859 On the origin of species).

Symmetry: From the variant of syn- meaning together, and the Greek metria meaning measure. Literally, the measure of things together, or side by side.

Sym-: A different form of syn- meaning together.

Syn-, Sym-: From ancient Greek sun- meaning with, together with, the same. English variation is syn, or sym.). Examples: synchronous (the same time); sympathy (same emotions); sympatric (species having the same geographic range).

Syncline: From ancient Greek the word element sun- meaning with, together with, the same, and Old English latinized word element -cline meaning lean, or fold, that is related to old French clinen or cliner meaning to bend. Use in geology to describe folded strata dates to early-mid 19^th C. The adjective synclinal was used on a more regular basis by Lyell and others (1830s). The history of geological usages parallels that for anticline.

System: From two ancient Greek roots – histanai and syn giving systema meaning to place in order or organize, thence to Latin systema and French système. Nicolaus Copernicus in his De Revolutionibus Orbium Coelestium, Libri VI (1543) referred to the systema of astronomy in the sense of it being based on a set of mathematical principles and observations.  The name Solar System is commonly attributed to Copernicus. Isaac Newton used the Latin noun systemate frequently in his Principia Mathematica (1686).

Taphonomy: The term coined by Russian paleontologist I. A. Efremov (1940), its etymology based on the Greek words taphos meaning burial or grave, and nomos meaning laws and nomia meaning method. The taphos element may also have PIE roots.

Taxon (plural taxa): A relatively late addition to evolutionary biology terminology, it first appeared in 1926 in a publication by German biologist Adolf Meyer-Abich referring to animal groups. It was formally introduced to the biological-paleontological lexicon in 1950 as a replacement of the term taxonomic group. Its root is the Greek taxis meaning division or arrangement of.

Tectonic: From Greek tektonikos and Latin tectonicus. meaning building. It’s use in geology in the sense of mountain building is from the late 19^th C. It has been an important concept in theories on the origin of the Earth, continents, oceans, mountain ranges, and Earth movements since the early 1800s.

The present is the key to the past: An oft-quoted phrase based on the principle espoused by James Hutton (1895) that present processes and conditions can be used to infer past geological processes in the rock record. The principle is one of the foundations of geological interpretation. Hutton did not use the phrase – Charles Lyell coined it to paraphrase Hutton in “Principles of Geology” 1830. The phrase is also encapsulated in the extended title to Principles of Geology: Being an Inquiry How Far The Former Changes of the Earth’s Surface are Referable to Causes now in Operation.

Therm-: A word element of Greek origin – thermos meaning heat, or temperature, and probably of older PIE roots. Examples: prefixes – thermodynamic, thermometer, thermostat. Suffixes – hydrothermal, hypsithermal.

Thermodynamic: Using the Greek prefix therm, was introduced in 1854 by British physicist William Thompson, a.k.a. Lord Kelvin, in a publication on the Theory of Heat. The Laws of thermodynamics were formulated a little later – Rudolph Clausius derived the First and Second Laws in 1850, later called the 1^st and 2^nd Laws of Thermodynamics.

Tidal wave: The term commonly applied in English for large earthquake-generated waves, later replaced by the Japanese word tsunami (entry below). Tidal wave is still used, but it is technically incorrect.

Tide: Probably of Proto-German tīdi- meaning division of time, or possibly older PIE, thence to Old English tid and Middle English tide. Time contexts gave rise to Middle English words like betide, anytide and tideful. In the word Yuletide the word element yule is from Old Norse Jol that refers to a pagan festival – thus yuletide is the time of the festival.  The reference to ocean tides is about early 14^th C and originally had a time connotation – the time of the tide; in the Middle English expression time and tide the words are synonymous. Qualifications as to ebb and flood tides is 16^th or 17^th C – Lord Bacon’s Novum Organum (1620) refers to the coincidence of flood tides from place to place “Now Acosta, and some others, after a diligent inquiry, have observed that the flood tide takes place on the coast of Florida, and the opposite coasts of Spain and Africa, at the same time,”. The adjective tidal may be early 19^th C.

Till: As a preposition it has Proto-German and Old English roots (til), meaning onward or up to (in time). The verb form is more commonly associated with plowing or turning soil, again from pre-Old English. As a place box or other device to keep money, is probably Middle English time. The geological sense of stiff, clay or mud-rich deposit that includes a broad range of clast sizes (usually of glacial origin) appears to be 17^th C Scottish but the source is unknown. It may be the case that an association with plowing or turning sod is relevant, given that stiff clays are difficult to manage.

Time: As a noun, verb and adjective. The noun is probably Proto-German tima, thence Old English tima as in duration, extent, or tid meaning period or season. The Middle English spelling was time and tyme. From the 14^th C on it is used in many expressions, such as many times, the right time, and as a word element as in the Middle English somtyme (sometime) and mene tyme (meantime). The OE preposition æfter or after is an associated form meaning later in time, or behind. The oldest written expression of the well-known phrase “time and tide wait for no man” is 1225 by St. Mahrer, about whom I cannot find information: “And te tide and te time þat tu iboren were, schal beon iblescet,”. Another version of it was also used by Chaucer in the Clerk’s Prologue (1395) – “For thogh we slepe, or wake, or rome, or ryde, Ay fleeth the tyme; it nyl no man abyde.” Chaucer also provides us with one of the earliest uses of the expression “space and tyme”.

Tool: (noun) Probably originates with PIE languages, but the first clearly recognizable form is Proto-German tola or tōwalan meaning an implement (5^th C BCE to 5^th CE), thence to Old English tol. The modern spelling tool is from Middle English.

Tool-mark: A term in sedimentology indicating the scratches, grooves or some other excavations created by objects that move across a soft sediment surface. The OED puts the first use as 1860, probably as the mark left by a craftsperson, engraver, or carpenter.

Topo-: From ancient Greek topos meaning place, region.     Examples: topography – the study and mapping of landforms and landscapes; topology – the properties of objects and spaces that do not change during deformation (mathematician Johann Listing in 1947.

Trans-: A word element (suffix) from the Latin preposition trans meaning across, through, or from one state to another as in transition, transparent, transcurrent.

Tri-: A prefix meaning three of, trio, derived from Latin tres, French trés, or Greek trias. Examples: Trigonal (one of the main crystal symmetry groups); triangle.

-trophic: Can be an adjective on its own, as in trophic level in a food chain, or a word element. From the Greek trophe and trophikos meaning food, nourishment, or nutrition. Thus autotrophic (self feeding), heterotrophic (relies on other organisms to feed).

Tropic: From the Greek tropikos meaning “belonging to a turn of the sun at the solstice,” from the Greek participle trope, later the Latin tropicus. Defined originally as the limits north and south on the celestial sphere of ecliptic, corresponding to the limits where the course of the Sun reverses. The Tropics of Cancer (The Crab) and Capricorn were defined by Greek astronomers one or two centuries BCE, and later named when the Sun lay in the constellation of the same names (those positions have since changed because of Earth’s precessional wobble). It is currently at latitude 23°27′ north; Tropic of Capricorn is 23°27′ south.

True: (adjective) From Proto-German treuwaz to Old English triewe, trewe, and treowe meaning faithful, honest. The Middle English forms include treu. The Middle English verb trowen means to believe (to be true). The opposite untrewe means not true. There is also the Middle English word lel which means true as in loyal, and soth which means truth, or sooth. True has a different etymology to its antonym false.

Truth: The noun form in Middle English trouthe and its opposite untrewthe are from the same Proto-German and Old English roots for the adjective ‘true’.

Tube: From the Latin tubus and French tube meaning pipe or conduit. It originally referred to anatomical tubes in people and animals (16^th C). The OED has the earliest use in English as 1651, but (Lord) Francis Bacon’s Novum Organum (1620) uses tube in several parts of his text which suggests it’s presence was more widespread much earlier than 1651. The context of Bacon’s use extended to glass tubes used in experiments. Robert Hooke (1665) likewise uses tube in this sense (constructed tubes) but extends its meaning to natural anatomical tubes in a flea that he observed under a microscope (e.g., p. 210). The earliest references I have found to lava tube are Chester Wentworth (1925), and Henry Palmer (1929) for Hawaiian examples – see the entry for lava tube.

-tude: Formed from the word element -ude, from Latin –udo and French -ude. Forms nouns from other word elements like alti-tude, magni-tude, multi-tude.

Turbid: From Latin (adjective) turbidus and the verb turbare meaning muddy, confusion as in a crowd. Probably 17^th C English. From which we get disturb, perturb, turbidity, turbidite, turbulent.

Tsunami: A Japanese word, adopted into English common language, that is based on two words – Tsu meaning harbour, and nami meaning wave – an appropriate conjoining of words given that these forces of nature really come into their own along shallow coasts and harbours. It apparently entered the English language via the National Geographic Magazine that reported on a major earthquake wave on June 15, 1896, off the coast of Honshu. Prior to this introduction, the name tidal wave was, and still is applied, albeit incorrectly. Although records of tsunami date back almost 2000 years in Japan (in manuscripts and art), one of the earliest printed versions of the word is in an account of the Sanriku earthquake of 2 December 1611 by Tokugawa Ieyasu (in Cartwright and Nakamura, 2008 (Tsunami: A history of the term and of scientific understanding of the phenomenon in Japanese and Western culture).

Turbidite: From the Latin root turbidus meaning muddy and disturbed. Introduced by Philip Kuenen at the 18th International Geological Congress in Great Britain, 1948 – the title of his talk Turbidity currents of high density. Kuenen published the term in 1950 – Turbidity currents of high density. In W. B. Harland, O. T. Jones (Eds.), Proceedings of section G, the geology of sea and ocean floors (pp. 44–52). London: IGC. The publication came on the heels of another influential paper by Kuenen and Migliorini on experimental turbidity currents; Kuenen, P. H., & Migliorini, C. I. (1950). Turbidity currents as a cause of graded bedding. The Journal of Geology,58, 91–127.

Two: From Proto-German and Old English twa, Old German zwo, and Modern German zwei. In Old English twa was feminine, the masculine form twegen later morphed to twain.

Un-: The Old English variant of the Latin prefix in-, denoting a negative of something, as in unnecessary, uncertain. Although the Latin prefix tends to be more correct, un- is still use in words like uncertain (instead of incertain), or unconformity (the opposite of conformity). The prefix un- also has roots in Old German. It has no relationship with the Latin word element uni-.

Unconformity: One of the earliest renderings of this word is from the English theologian Richard Hooker in his ‘Of the Laws of Ecclesiastical Polity’ published 1594-1597.   The meaning was essentially an antonym for conformity in Biblical and theological writings, meaning adherence to doctrinal laws. According to S.I. Tomkeieff (1962) there were several pictorial descriptions of unconformities before James Hutton, but no analysis of their stratigraphic import – such luminaries as Nicholas Steno I 1669, and John Strachy in 1719. The geological meaning of unconformity as a stratigraphic surface, derived from the absence of conformity of sediment composition and/or structural geometry in successions of strata, the surface also representing missing time. James Hutton, in his ‘Theory of the Earth first published 1788, and later in 1795, was the first to describe the properties and conditions for unconformities, but he never used the word. That accolade is accorded to Robert Jameson in 1805 who generally opposed Hutton’s theories. Hutton does use the word conformity but only in the sense of conforming with an idea.

Uni-: Common prefix from Latin uni- meaning one of, unique, a singularity. Examples: unique, unidirectional, universe

Uniformity: From Latin uniformis meaning a singular shape or form, to Old French uniformite as continuing on a course or sameness. From a philosophical perspective, uniformity provides a warrant inductive inferences about the past based on the proposition that processes and actions have remained the same. In geology the concept of uniformity was popularized by Charles Lyell, initially in his book “Principles of Geology” (1830-1832), referring to the continuation or steady-state of Earth processes through time and the invariance of natural laws. Lyell based his interpretation of uniformity partly on James Hutton’s views of the immensity of time, where natural processes resulting in landscapes, mountain belts and oceans progressed with the same intensity and as uniformly in the distant past as they do today. It was the antithesis of catastrophism that 17-19^th C naturalists promoted; it was also a central tenet of Christian theology that catastrophes were a manifestation of God’s wrath at human folly.

Uniformitarianism: This variation on the word Uniformity was coined by polymath and commentator William Whewell (1794–1866) in his 1832 review and critique of Charles Lyell’s book “Principles of Geology” – Whewell expresses his doubts. This was published anonymously in The Quarterly Review, 1832, v. XLVII, p.126.

Up: (prep; adv)A common English preposition, probably from Proto-Indo European upo and Proto-German upp-, to Old English up and uppe meaning to place something higher than another, or toward a summit or high point.

Upper: (adj) From the Old English up and uppe meaning topmost, aloft, above. Hence Old English derivatives upende (upper end), ūpāstreccan (to uplift), uplic (heavenly, supreme), and Middle English up so doun (upside down) and Up-right or upryghte (upright). The sense of topmost or highest has been used frequently in science-geology since about 16^th C. The expression upper crust originally referred to bread, adopted in late 19^th C and 20^th C descriptions of Earth’s crust. The terms upper and lower were in common informal use in the 18^th C and 19^th C to relate the position of one set of strata to another. The more formal use of Upper and Lower was in use by early 19^th C as attested in William Smith’s Geological Map (1815) – as in Upper Greensand, Upper Paleozoic.

Uranium: The element discovered by chemist Martin Heinrich Klaproth in 1789, extracted from pitchblende (an ore composed mostly of UO₂) announced at a meeting of the Royal Prussian Academy of sciences in Berlin. He named it after the planet Uranus that had been discovered in 1781 by British astronomer William Herschel. Klaproth went on to discover zirconium (from the mineral zircon).

UTM: Universal Transverse Mercator – a geographic system used to assign coordinates on the Earth surface, where the surface is projected onto a flat plane – in other words it does not take altitude into account. Although the US Army Corp of Engineers is commonly credited with its introduction, there is evidence that the Wehrmacht may have used a similar system in 1942-43, referring to it as UTMREF or UTM Reference System.

Variable: (noun and adjective) From the Latin variabilis meaning change, from the root vary, then Old French variable meaning changeable, fickle in late 14^th C. Also subject to change from about the 14^th C. As a changeable quantity that can be measured  – the concept of unknown quantities that can be solved dates back to ancient Greece, for example in Euclidian geometric solutions. Francis Bacon’s Novum Organum (1620) uses the word more explicitly as in “heat is variable, and can approach or retire;” René Descartes in 1637 posited the use of letters like x, y for unknown quantities that could be solved for in functions such as quadratic equations, although he didn’t call them variables. Newton in his Principia (1686) uses expressions like “inclinatio variabitur,” (the inclination will vary), and “uniformi circa axem unicum inclinatione semper invariabili datum.” (given a uniform inclination about a single axis, always invariable). Dependant variables in a mathematical function depend on the value of other variables deemed to be independent. Thus, in the equation y = mx + c a unique value of y depends on values given to x.

Vein: Originally associated with blood vessels, channels from Latin vena, and 13^th C Old French veine. Thence Middle English veyne (borrowing the Norman word). It’s meaning as a mineral deposit probably from Middle English. Its more figurative meaning as a reference to style, mood, or having a particular quality probably dates from 15^th – 16^th C – e.g., Rabelais (b? – 1553.

Velocity: From Latin velocitatemand velocitas meaning speed, quickness, rapidity. The expression of velocity was probably first enumerated by Galileo who discovered the concept of acceleration, expressed as the distance travelled per the square of time (e.g., m.s^-1.s^-1), and that velocity could be expressed as the acceleration multiplied by time i.e., the expression for acceleration reduces to m.s^-1. Newton later devised the calculus that enabled the calculation of instantaneous velocity.

Versus: From 15^th century Latin versus meaning turned toward or against, but having a from  proto-Indian-European root wer… meaning “to turn” (proto-Indian-European language is supposed to have arisen during the Late Neolithic to Early Bronze Age, 4500 BC to 2500 BC.

Vesicle: From the Latin noun vesica meaning a blister, or bladder, and the Latin vesicula that also refers to anatomical structures. Thence to French vesicule. One of the earliest references to vesicle in geological literature is A. Geikie’s Text-Book of Geology, 1882, where he discusses microscopic. liquid-filled cavities, vacuoles, inclusion, or vesicles in crystals (p. 98). James Hutton (1795) discusses the origin of amygules, or amygdaloids (mineral-filled vesicles), but not the vesicles sensu stricto.

Viz.  From Latin videre licet that in contracted form videlicet means “it is permitted to see”. The contraction in English is commonly used for namely or that is. It provides a way to expand or clarify a previous statement. In a sentence it should be separated by a comma.

Volcano: Vulcan was the God of fire and metal, as in molten metal, in Roman mythology. Descriptions of Vesuvius eruption in 79 CE by Pliny the Younger are perhaps some of the earliest recordings from a volcanological perspective. This link contains both Latin and translated versions of Pliny’s letters.  From the Latin Volcanus, or Vulcanus, and Italian volcano in reference to Mt Etna. In common use at least from 16^th C, with reference to either Vulcan the deity, or to fire and brimstone. In 1808 Humboldt described detailed some observations of the later eruption stages of Chimborazo in Ecuador. The first volcanological observatory in 1841, the Vesuvius Observatory, was founded by Giuseppe Mercalli, also of earthquake magnitude fame (the observatory still operates).

Volume: The noun form is from Latin volumen and volumin meaning a roll usually in the context of a manuscript, and the verb volvere – to roll (up). This was taken up by Old French volume and the latest Middle English (late 14^th C). Another Middle English derivative is envolupen (to wrap up).  The word generally referred to books and manuscripts. The scientific connotation of size in relation to mass derives from the size of books, probably 17^th C. Lord Bacon (Novum Organum, 1620) uses the word in both senses, as a number of books, and in the context of size “…Let the fourth be that which we term the motion of matter, and which is opposed to the last; for in the motion of liberty, bodies abhor, reject, and avoid, a new size or volume, or any new expansion or contraction…” (Section XLVIII).   Antoine Lavoisier in his Traité élémentaire de Chimie (1789) uses volume in the context of size “& si on le ramène à la même température qu’il avoit en commençant l’expérience, il reprend sensiblement le volume qu’il avoit d’abord.” (and if we bring it back to the same temperature that it had when starting the experiment, it substantially regains the volume that it had at first.).

-ward: A common adverbial suffix from Proto German werda and German –warts meaning to turn or bend (towards), thence Old English -weard meaning toward, as in forward, basinward, shoreward.

Water: Probably from proto-German watr- that later morphed into Old German wasser, Norse vatn, and Russian voda. Also Anglo-Saxon (Old English) as in the heroic poem Beowulf use of wæter (debated 8^th C – 11^th C). Note that the ancient Greek word for water was hydro,that forms a common prefix for words like hydrogeology, hydrodynamic, hydrostatic

Wave (verb): From proto-German wab, thence to Old English wafian meaning to fluctuate, or move back and forth. As in the famous Royal wave.

Wave (noun): From the verb, something that moves to and fro, as in water waves. The epic poem Beowulf uses the word wǣg, a variation on wab or wag.   Leonardo da Vinci illustrated waves in his notebook entries on experimental flow in flumes, for example in Codex Leicester, f. 9 verso (f. 9v), one of the first descriptions of wave motion. He is also credited with the discovery of sound waves in 1490. The term wave-dominated is probably 20^th C, popularised during the burgeoning studies of sedimentary facies, processes, and depositional systems from about 1960s on.

Wedge: Noun form from proto-German wagjaz and thence Old English wecg, as in things shaped like… The verb form dates at least to 15^th C.

Whole: From Proto-German haila- meaning undamaged, and Old English hal, thence Middle English hole meaning complete, entire, or safe; also Middle English hail as in hale or sound, hence hailsome – wholesome.

Wilson Cycle: A fundamental concept that outlines the important stages in the evloution of ocean basins. The name was coined following a seminal paper by Tuzo Wilson in 1966 – a time when the plate tectonic revolution was in its infancy. J.T. Wilson, 1966. Did the Atlantic close and then re-open? Nature, 211, 676–681. There are 6 stages to the cycle: (1) Rifting of continental crust-lithosphere. (2) Opening of a nascent ocean basin by sea floor spreading. (3) Drift of the two continental blocks and formation of a mature ocean basin. (4) Initiation of a subduction zone. (5) Subduction of oceanic lithosphere and closure of the ocean basin. (6) Continent-continent collision and formation of mountain belts and orogenic sutures.

Winnow: Derived from Old English windwian, meaning ‘from the wind‘. Commonly referred to the separation of wheat from its chaff, using the wind. Its sedimentological connotation is probably early 20^th C.

x: The multiplication sign probably arose in the 16 th or 17 th C when it was referred to as the Cross of San Andres (Saint Andrew, a martyred Apostle), although this sign originally signified both multiplication and division. William Oughtred (1574 – 1660), an English mathematician, determined that it should only signify multiplication. Apparently, Newton and Liebniz both objected to it because it looked too much like an alphabetic X and the Roman number ten; Johann Bernoulli replaced it with a dot (elevated above the bottom line), so instead of 3 x 2 he wrote 3·2.

X-ray: Coined in 1895 by Wilhelm Conrad Röntgen (1845-1923), the discoverer. The ‘X’ signified an unknown, because he could not identify the exact nature of the radiation. The word ray stems from the anglicised form of the German strahl, meaning ray or beam, for which he received the Nobel Prize in Physics in 1901.

Zero (0): Zero is an invention. It is a place holder, which means it occupies the place where no integer occurs. So, in the number 1001, the zeros indicate that there are no 10s or 100s integers. The place number in this case is constructed around a base of 10 but it can be used for any base value. Place value was probably invented by the Babylonians about 2000 BC. The oldest known manuscript that uses a dot as place holder, is found in the 3^rd – 4^th century Bakhshali manuscript. The oldest known use of the symbol 0, instead of a dot, is recorded in a 9^th Century Hindu temple. The first definition of zero as an actual number was made in 628 AD by Hindu astronomer and mathematician Brahmagupta. Leonardo of Pisa (a.k.a. Fibonacci) introduced Arabic numerals to western culture in 1202, including the ‘0’ notation.

-zoic From Greek zoikos meaning life, animal life. Examples: Paleozoic – coined by Adam Sedgewick in 1838 for the era where fossils resemble modern life forms. Proterozoic – (late 19^th C) originally coined for the geological period that contains the earliest record of life, where fossils do not resemble modern metazoan forms.

Zoo- From Greek zoion meaning a living being or animal. Examples: zooid, Zoophycus, zoology, zooxanthella. Note that term zoo meaning a place to visit live animals is a mid-19^th C shortening of the title given to the Zoological Gardens of the London Zoological Society in 1847.