covalent (adj.) Look up covalent at Dictionary.com
1929, from covalence (1919), from co- + valence.
covariance Look up covariance at Dictionary.com
1878, from covariant (1853), from co- + variant.
cove (n.1) Look up cove at Dictionary.com
early 14c., "den, cave," from Old English cofa "small chamber, cell," from Proto-Germanic *kubon (compare Old High German kubisi "tent, hut," German Koben "pigsty," Old Norse kofi "hut, shed"). Extension of meaning to "small bay" is 1580s, apparently via Scottish dialectal meaning "small hollow place in coastal rocks" (a survival of an Old English secondary sense).
cove (n.2) Look up cove at Dictionary.com
"fellow, chap," slang from at least 1560s, said to be from Romany (Gypsy) cova "that man."
coven (n.) Look up coven at Dictionary.com
"a gathering of witches," 1660s, earlier (c. 1500) a variant of covent, cuvent early forms of convent. Association with witches arose in Scotland, but not popularized until Sir Walter Scott used it in this sense in "Letters on Demonology and Witchcraft" (1830).
Efter that tym ther vold meit bot somtymes a Coven, somtymes mor, somtymes les; bot a Grand Meitting vold be about the end of ilk Quarter. Ther is threttein persones in ilk Coeven; and ilk on of vs has an Sprit to wait wpon ws, quhan ve pleas to call wpon him. I remember not all the Spritis names; bot thair is on called "Swein," quhilk waitis wpon the said Margret Wilson in Aulderne; he is still clothed in grass-grein .... ["Criminal Trials in Scotland," III, appendix, p.606, confession of Issobell Gowdie in Lochloy in 1662]
covenant (v.) Look up covenant at Dictionary.com
c. 1300, from covenant (n.). Related: Covenanted; covenanting. Covenanter (1638) was used especially in reference to Scottish Presbyterians who signed the Solemn League and Covenant (1643) for the defense and furtherance of their cause.
covenant (n.) Look up covenant at Dictionary.com
c. 1300, from Old French covenant "agreement," originally present participle of covenir "agree, meet," from Latin convenire "come together, unite; be suitable, agree," from com- "together" (see com-) + venire "to come," from a suffixed form of PIE root *gwa- "to go, come." Applied in Scripture to God's arrangements with man as a translation of Latin testamentum, Greek diatheke, both rendering Hebrew berith (though testament also is used for the same word in different places).
covent (n.) Look up covent at Dictionary.com
early form of convent (n.) in use to 17c.
Coventry Look up Coventry at Dictionary.com
city in Warwickshire, Old English Couentre (1043) "Cofa's tree," from Old English masc. personal name Cofa (genitive Cofan) + tree (n.). Probably a boundary marker or public assembly place.
cover (n.) Look up cover at Dictionary.com
early 13c., in compounds, from cover (v.). Meaning "recording of a song already recorded by another" is 1966. Cover girl is U.S. slang from 1915, shortening of magazine-cover girl.
cover (v.) Look up cover at Dictionary.com
mid-12c., from Old French covrir (12c., Modern French couvrir) "to cover, protect, conceal, dissemble," from Late Latin coperire, from Latin cooperire "to cover over, overwhelm, bury," from com-, intensive prefix (see com-), + operire "to close, cover," from PIE compound *op-wer-yo-, from *op- "over" (see epi-) + root *wer- (4) "to cover."

Related: Covered; covering. Military sense is from 1680s; newspaper sense first recorded 1893; use in football dates from 1907. Betting sense is 1857. Of horses, as a euphemism for "copulate" it dates from 1530s. Covered wagon attested from 1745.
cover-up (n.) Look up cover-up at Dictionary.com
also coverup, "means or act of concealing" some event or activity, 1922, from verbal phrase, from cover (v.) + up (adv.).
coverage (n.) Look up coverage at Dictionary.com
mid-15c., "charge for a booth at a fair," from cover + -age. Reintroduced 1912, American English, in insurance.
coverlet (n.) Look up coverlet at Dictionary.com
c. 1300, perhaps a diminutive of cover (n.), but early form coverlite suggests an unrecorded Old French or folk-etymology *covre-lit, from covrir "to cover" + lit "bed" (see litter (n.)).
covert (adj.) Look up covert at Dictionary.com
c. 1300, from Old French covert "hidden, obscure, underhanded," literally "covered," past participle of covrir "to cover" (see cover (v.)). Related: Covertly.
coverture (n.) Look up coverture at Dictionary.com
early 13c., earliest reference is to bedcovers, from Old French coverture (12c.) "blanket; roof; concealment," from Latin *coopertura, from past participle stem of cooperire "to cover" (see cover (v.)). Most modern senses had evolved by mid-15c.
covet (v.) Look up covet at Dictionary.com
mid-13c., from Old French coveitier "covet, desire, lust after" (12c., Modern French convoiter, influenced by con- words), probably ultimately from Latin cupiditas "passionate desire, eagerness, ambition," from cupidus "very desirous," from cupere "long for, desire" (see cupidity). Related: Coveted; coveting.
covetous (adj.) Look up covetous at Dictionary.com
mid-13c., from Old French coveitos (12c., Modern French convoiteux) "desirous, covetous," from Vulgar Latin *cupiditosus, from Latin cupiditas (see covet). Related: Covetously; covetousness.
covey (n.) Look up covey at Dictionary.com
mid-14c., "brood of partridges," from Middle French covée "brood" (Modern French couvée), from Gallo-Roman *cubata, literally "hatchling," from past participle stem of Latin cubare "to sit, incubate, hatch" (see incubation).
cow (v.) Look up cow at Dictionary.com
"intimidate," c. 1600, probably from Old Norse kuga "oppress," which is of unknown origin, but perhaps having something to do with cow (n.) on the notion of easily herded. Related: Cowed; cowing.
cow (n.) Look up cow at Dictionary.com
Old English cu "cow," from Proto-Germanic *kwon (source also of Old Frisian ku, Middle Dutch coe, Dutch koe, Old High German kuo, German Kuh, Old Norse kyr, Danish, Swedish ko), earlier *kwom, from PIE root *gwou- "ox, bull, cow."
cowabunga (interj.) Look up cowabunga at Dictionary.com
1954, American English, from exclamation of surprise and anger by "Chief Thunderthud" in "The Howdy Doody Show," 1950s children's TV show; used by surfers 1960s as a shout of triumph, and spread worldwide 1990 by use in the TV cartoon "Teenage Mutant Ninja Turtles."
coward (n.) Look up coward at Dictionary.com
mid-13c., from Old French coart "coward" (no longer the usual word in French, which has now in this sense poltron, from Italian, and lâche), from coe "tail," from Latin coda, popular dialect variant of cauda "tail," which is of uncertain origin + -ard, an agent noun suffix denoting one that carries on some action or possesses some quality, with derogatory connotation (see -ard).

The word probably reflects an animal metaphoric sense still found in expressions like turning tail and tail between legs. Coart was the name of the hare in Old French versions of "Reynard the Fox." Italian codardo, Spanish cobarde are from French.
The identification of coward & bully has gone so far in the popular consciousness that persons & acts in which no trace of fear is to be found are often called coward(ly) merely because advantage has been taken of superior strength or position .... [Fowler]
As a surname (attested from 1255) it represents Old English cuhyrde "cow-herd." Farmer has coward's castle "a pulpit," "Because a clergyman may deliver himself therefrom without fear of contradiction or argument."
cowardice (n.) Look up cowardice at Dictionary.com
c. 1300, from Old French coardise (13c.), from coard, coart (see coward) + noun suffix -ise.
Cowardice, as distinguished from panic, is almost always simply a lack of ability to suspend the functioning of the imagination. [Ernest Hemingway, "Men at War," 1942]
cowardly (adj.) Look up cowardly at Dictionary.com
1550s, from coward + -ly (1). The adverb (late 14c.) is much older than the adjective:
Yit had I levir do what I may Than here to dye thus cowerdelye ["Le Morte d'Arthur," c. 1450]
An Old English word for "cowardly" was earg, which also meant "slothful." Related: Cowardliness.
cowbell (n.) Look up cowbell at Dictionary.com
1650s, American English, from cow (n.) + bell (n.).
cowboy (n.) Look up cowboy at Dictionary.com
1725, "boy who tends to cows," from cow (n.) + boy. Sense in Western U.S. is from 1849; in figurative use by 1942 for "brash and reckless young man" (as an adjective meaning "reckless," from 1920s). Cowhand is first attested 1852 in American English (see hand (n.)). Cowpoke (said to be 1881, not in popular use until 1940s) was said to be originally restricted to the cowboys who prodded cattle onto railroad cars with long poles.
cower (v.) Look up cower at Dictionary.com
c. 1300, probably from Middle Low German *kuren "lie in wait" (Modern German kauern), or similar Scandinavian words meaning "to squat" and "to doze" (such as Old Norse kura, Danish, Norwegian kure, Swedish kura). Thus unrelated to coward. Related: Cowered; cowering.
cowl (n.) Look up cowl at Dictionary.com
Old English cule, from earlier cugele, from Late Latin cuculla "monk's cowl," variant of Latin cucullus "hood, cowl," which is of uncertain origin. Cowling is 1917 in the aircraft sense.
cowlick (n.) Look up cowlick at Dictionary.com
1590s, from cow (n.) + lick (n.). Because it looks like a cow licked your head.
coworker (n.) Look up coworker at Dictionary.com
also co-worker, 1640s, from co- + worker (n.).
Cowper's gland (n.) Look up Cowper's gland at Dictionary.com
1738, so called because discovered by anatomist William Cowper (1666-1709); see Cooper.
cowrie (n.) Look up cowrie at Dictionary.com
small shell, used as money in parts of Asia, 1660s, from Hindi and Urdu kauri, from Mahrati kavadi, from Sanskrit kaparda, perhaps related to Tamil kotu "shell."
cowslip (n.) Look up cowslip at Dictionary.com
Old English cu-slyppe, apparently from cu "cow" (from PIE root *gwou- "ox, bull, cow") + slyppe "slop, slobber, dung" (see slop (n.1)).
Cox Look up Cox at Dictionary.com
surname, from early 16c., earlier Cocks (c. 1300), in many cases from cock (n.1), which apparently was used as a personal name in Old English, also as a familiar term for a boy, later used of apprentices, servants, etc. Perhaps in some cases for the sign of an inn. In some cases perhaps from cook (n.), or Welsh coch "red."
coxcomb (n.) Look up coxcomb at Dictionary.com
1570s, from cokkes comb (1560s, see cockscomb). Johnson has coxcomical (adj.) "foppish, conceited," but discourages it as "a low word unworthy of use."
coxswain (n.) Look up coxswain at Dictionary.com
early 14c., "officer in charge of a ship's boat and its crew," from cock "ship's boat" (from Old French coque "canoe") + swain "boy," from Old Norse sveinn "boy, servant" (see swain).
coy (adj.) Look up coy at Dictionary.com
early 14c., "quiet, modest, demure," from Old French coi, earlier quei "quiet, still, placid, gentle," ultimately from Latin quietus "resting, at rest" (see quiet (n.)). Meaning "shy" emerged late 14c. Meaning "unwilling to commit" is 1961. Related: Coyly; coyness.
coyote (n.) Look up coyote at Dictionary.com
1759, American English, from Mexican Spanish coyote, from Nahuatl (Aztecan) coyotl.
coz (n.) Look up coz at Dictionary.com
1550s, familiar abbreviation of cousin.
coze (v.) Look up coze at Dictionary.com
to chat, 1828, of uncertain origin; perhaps from French causer "to talk," from Latin causari "to plead, dispute, discuss a question," from causa (see cause (n.)).
cozen (v.) Look up cozen at Dictionary.com
1560s, of uncertain origin; perhaps from French cousiner "cheat on pretext of being a cousin;" or from Middle English cosyn "fraud, trickery" (mid-15c.), which is perhaps related to Old French coçon "dealer, merchant, trader," from Latin cocionem "horse dealer." Related: Cozened; cozening; cozenage.
cozy (adj.) Look up cozy at Dictionary.com
1709, colsie, Scottish dialect, perhaps of Scandinavian origin (compare Norwegian kose seg "be cozy"). In Britain, usually cosy. Related: Cozily; coziness.
cpr Look up cpr at Dictionary.com
by 1979, abbreviation of cardiopulmonary resuscitation.
cpu Look up cpu at Dictionary.com
by 1970, abbreviation of central processing unit.
crab (n.1) Look up crab at Dictionary.com
crustacean, Old English crabba, from a general Germanic root (compare Dutch krab, Old High German krebiz, German Krabbe, Old Norse krabbi "crab"), related to Low German krabben, Dutch krabelen "to scratch, claw," from PIE root *gerbh- "to scratch, carve" (see carve). The constellation name is attested in English from c. 1000; the Crab Nebula (1840), however, is in Taurus, the result of the supernova of 1054, and is so called for its shape. French crabe (13c.) is from Germanic, probably Old Norse.
crab (n.2) Look up crab at Dictionary.com
"fruit of the wild apple tree," c. 1300, crabbe, perhaps from Scandinavian (compare Swedish krabbäpple), of obscure origin. The combination of "bad-tempered, combative" and "sour" in the two nouns crab naturally yielded a verb meaning of "to vex, irritate" (c. 1400), later "to complain irritably, find fault" (c. 1500). The noun meaning "sour person" is from 1570s.
crabbed (adj.) Look up crabbed at Dictionary.com
late 14c., "peevish, angry, ill-tempered," from crab (n.1), from the crab's combative disposition; mid-15c. as "resembling a crab" in reference to crookedness. Of taste "bitter, harsh," late 14c., from crab (n.2).
crabby (adj.) Look up crabby at Dictionary.com
1520s, in now-obsolete sense "crooked, gnarled, rough," from extended sense of crab (n.1) + -y (2). Meaning "disagreeable, sour, peevish" is attested from 1776, American English. Both senses were found earlier in crabbed.
crabgrass (n.) Look up crabgrass at Dictionary.com
c. 1600, from crab (n.1) + grass. Originally a marine grass of salt marshes; modern meaning is from 1743. Perhaps partly for its crooked form.