Online Etymology Dictionary

coolth (n.): 1540s, from cool on the model of warmth. It persists, and was used by Pound, Tolkien, Kipling, etc., but it never has shaken its odor of facetiousness and become standard.
coomb (n.): also combe, "deep hollow or valley, especially on flank of a hill," mainly surviving in place names, from Old English cumb, probably a British word, from Celtic base *kumbos (compare Welsh cwm in same sense). Cambridge Dictionary of English Place-Names says, "This is usually taken to be a Celtic loan ... but there was also OE cumb 'vessel, cup, bowl,'" which was "probably used in a transferred topographical sense reinforced in western districts by cwm."
coon (n.): short for raccoon, 1742, American English. It was the nickname of Whig Party members in U.S. c. 1848-60, as the raccoon was the party's symbol, and it also had associations with frontiersmen (who stereotypically wore raccoon-skin caps), which probably ultimately was the source of the Whig Party sense (the party's 1840 campaign was built on a false image of wealthy William Henry Harrison as a rustic frontiersman).

The insulting U.S. meaning "black person" was in use by 1837, said to be ultimately from Portuguese barracoos "building constructed to hold slaves for sale." No doubt boosted by the enormously popular blackface minstrel act "Zip Coon" (George Washington Dixon) which debuted in New York City in 1834. But it is perhaps older (one of the lead characters in the 1767 colonial comic opera "The Disappointment" is a black man named Raccoon). Coon's age is 1843, American English, probably an alteration of British a crow's age.
coop (n.): "small cage for poultry," mid-14c., from Old English cype, cypa "basket, cask," akin to Middle Dutch kupe, Swedish kupa, and all probably from Latin cupa "tub, cask," from PIE *keup- "hollow mound" (see cup (n.)).
coop (v.): 1560s, from coop (n.). Related: Cooped; cooping.
cooper (n.): "craftsman who makes wooden vessels," attested from late 12c. as a surname, either from Old English (unattested) or from a Low German source akin to Middle Dutch cuper, East Frisian kuper, from Low German kupe (German Kufe) "cask," cognate with Medieval Latin cupa (see coop (n.)).
A dry cooper makes casks, etc., to hold dry goods, a wet cooper those to contain liquids, a white cooper pails, tubs, and the like for domestic or dairy use. [OED]
The surname Cowper (pronounced "cooper") preserves a 15c. spelling.
cooperate (v.): also co-operate, c. 1600, from Late Latin cooperatus, past participle of cooperari "to work together with" (see cooperation). Related: Cooperated; cooperating.
cooperation (n.): late 15c., from Middle French coopération, or directly from Late Latin cooperationem (nominative cooperatio) "a working together," noun of action from past participle stem of cooperari "to work together," from com- "with" (see com-) + operari "to work" (see operation).
cooperative (adj.): also co-operative, c. 1600, from Late Latin cooperat-, past participle stem of cooperari (see cooperation) + -ive. Political economy sense is from 1808, from the pre-Marx communist movement. The noun meaning "a cooperative store" is from 1883; meaning "a cooperative society" is from 1921.
coopt (v.): see co-opt.
cooptation (n.): 1530s, "election to fill a vacancy," from Latin cooptationem (nominative cooptatio) "election," noun of action from past participle stem of cooptare (see co-opt). Related: Cooptative.
coordinate (adj.): 1640s, "of the same order," from Medieval Latin coordinatus, past participle of coordinare "to set in order, arrange" (see coordination). Meaning "involving coordination" is from 1769. Related: Coordinance.
coordinate (n.): 1823, in the mathematical sense, especially with reference to the system invented by Descartes; from coordinate (adj.). Hence, coordinates as a means of determining a location on the earth's surface (especially for aircraft), attested by 1960.
coordinate (v.): 1660s, "to place in the same rank," from Latin coordinare (see coordination). Meaning "to arrange in proper position" (transitive) is from 1847; that of "to work together in order" (intransitive) is from 1863. Related: Coordinated; coordinating.
coordination (n.): also co-ordination, c. 1600, "orderly combination," from French coordination (14c.) or directly from Late Latin coordinationem (nominative coordinatio), noun of action from past participle stem of Latin coordinare "to set in order, arrange," from com- "together" (see com-) + ordinatio "arrangement," from ordo "order" (see order (n.)). Meaning "action of setting in order" is from 1640s; that of "harmonious adjustment or action," especially of muscles and bodily movements, is from 1855.
coordinator (n.): also co-ordinator, 1864, agent noun in Latin form from coordinate (v.).
coot (n.): c. 1300, cote, used for various water fowl (now limited to Fulica atra and, in North America, F. americana), of uncertain origin. Compare Dutch meercoet "lake coot." Meaning "silly person, fool" is attested from 1766.
cooter (n.): name for some types of freshwater terrapin in southern U.S., 1835 (first attested 1827 in phrase drunk as a cooter, but this probably is a colloquial form of unrelated coot), from obsolete verb coot "to copulate" (1660s), which is of unknown origin. The turtle is said to copulate for two weeks at a stretch.
cootie (n.): "body lice," 1917, British World War I slang, earlier in nautical use, said to be from Malay kutu "dog tick."
cooties (n.): 1917, see cootie.
cop (v.): 1704, northern British dialect, "to seize, to catch," perhaps ultimately from Middle French caper "seize, to take," from Latin capere "to take" (see capable); or from Dutch kapen "to take," from Old Frisian capia "to buy," which is related to Old English ceapian (see cheap). Related: Copped; copping.
cop (n.): "policeman," 1859, abbreviation of earlier copper (n.2), 1846, from cop (v.).
cop out: by 1942, noun and verb, "sneak off, escape," American English slang, probably from cop a plea (c. 1925) "plead guilty to lesser charges," probably from northern British slang cop "to catch" (a scolding, etc.); as in cop a feel "grope someone" (1930s); see cop (v.). Sense of "evade an issue or problem" is from 1960s.
copacetic (adj.): 1919, but it may have origins in 19c. U.S. Southern black speech. Origin unknown, suspects include Latin, Yiddish (Hebrew kol b'seder), Italian, Louisiana French (coupe-sétique), and Native American. None is considered convincing by linguists.
copasetic: see copacetic.
cope (v.): late 14c., "come to blows with," from Old French couper, earlier colper "hit, punch," from colp "a blow" (see coup). Meaning evolved 17c. into "handle successfully," perhaps influenced by obsolete cope "to traffic" (15c.-17c.), a word in North Sea trade, from the Flemish version of the Germanic source of English cheap. Related: Coped; coping.
Copenhagen: capital of Denmark, literally "merchant's port," from Danish køber "merchant," literally "buyer" (see cheap (adj.)), + havn "port" (see haven).
Copernican (adj.): 1660s, "pertaining to Copernicus."
Copernicus: Latinized form of name of Mikolaj Koppernigk (1473-1543), physician and canon of the cathedral of Frauenburg. His great work was "De Revolutionibus Orbium Coelestium."
copesetic (adj.): see copacetic.
copier (n.): 1590s, agent noun from copy (v.).
copilot (n.): 1927, from co- + pilot (n.).
coping (n.): c. 1600 as an architectural term, from cope (n.), the cape-like vestment worn by priests (14c.), a variant of cape. Coping saw attested by 1931.
copious (adj.): mid-14c., from Latin copiosus "plentiful," from copia "an abundance, ample supply, profusion, plenty," from com- "with" (see com-) + ops (genitive opis) "power, wealth, resources," from PIE root *op- (1) "to work, produce in abundance," (see opus). Related: Copiously.
coplanar (adj.): 1862, from co- + planar.
copout: see cop out.
copper (n.1): malleable metallic element, Old English coper, from Proto-Germanic *kupar (source also of Middle Dutch koper, Old Norse koparr, Old High German kupfar), from Late Latin cuprum, contraction of Latin Cyprium (aes) "Cyprian (metal)," after Greek Kyprios "Cyprus" (see Cyprus).

Latin aes originally was "copper," but this was extended to its alloy with tin, bronze, and as this was far more extensively used than pure copper, the word's primary sense shifted to the alloy and a new word evolved for "copper," from the Latin form of the name of the island of Cyprus, where copper was mined. Aes passed into Germanic (which originally did not distinguish copper from its alloys) and became English ore. In Latin, aes was the common word for "cash, coin, debt, wages" in many figurative expressions. Chemical symbol Cu is from cuprum.
copper (n.2): "policeman," 1846; agent noun from cop (v.).
copperhead (n.): Trigonocephalus contortrix, 1775, American English, so called for color markings between its eyes; see copper + head (n.). Poisonous "sneak snakes" (because they bite without warning), the name is said to have been first used in reference to Northerners suspected of Southern sympathies in Greeley's New York "Tribune," July 20, 1861. Charles H. Coleman, "The Use of the Term 'Copperhead' During the Civil War" ["Mississippi Valley Historical Review" 25 (1938), p.263] traces it to an anonymous letter against Ohio anti-war Democrats in the Cincinnati "Commercial" newspaper in the summer of 1861. It seems not to have been in widespread use until summer 1862.
coppice (n.): late 14c., "small thicket of trees grown for cutting," from Old French copeiz, coupeiz "a cut-over forest," from Vulgar Latin *colpaticium "having been cut," ultimately from Latin colaphus "a blow with the fist," from Greek kolaphos "blow, cuff" (see coup).
copra (n.): dried kernel of coconut, 1580s, from Portuguese copra (16c.), from Malayalam koppara (cognate with Hindi khopra) "coconut;" related to Hindi khopri "skull," from Sanskrit kharparah "skull."
copro-: word-forming element indicating "dung, filth, excrement," before vowels copr-, from Modern Latin copro-, from Greek kopros "dung," from PIE root *kekw-. Hence, coprology "study of obscene literature."
coprolalia (n.): "obsessive use of obscene language, either through mental illness or perversion," 1886, from French coprolalie, coined 1885 by de la Tourette, from copro- "dung, filth" + Greek lalia "talk, prattle, a speaking," from lalein "to speak, prattle," of echoic origin.
coprolite (n.): fossil dung, 1829, from copro- + -lite, from French, for -lithe, from Greek lithos "stone" (see litho-).
coprophagia (n.): 1906, in Havelock Ellis, Latinized from coprophagy (q.v.).
coprophagy (n.): 1891, from Modern Latin coprophagus, from Greek koprophagos "dung-eating," from kopros "dung" (see copro-) + -phagos (see -phagous). Related: Coprophagous.
coprophilia (n.): "attraction to defecation and feces," 1934, from copro- + -philia.
copse (n.): 1570s, "small wood grown for purposes of periodic cutting," contraction of coppice.
Copt (n.): "native monophosyte Christian of Egypt," 1610s, from Modern Latin Coptus, from Arabic quft, probably from Coptic gyptios, from Greek Agyptios "Egyptian." Arabic has no -p- and often substitutes -f- or -b- for it. Related: Coptic.
copula (n.): linking verb, 1640s, from Latin copula "that which binds, rope, band, bond" (see copulate).