Online Etymology Dictionary

cow (v.): 1605, probably from O.N. kuga "oppress," of unknown origin, but perhaps having something to do with cow (n.) on the notion of easily herded.
cowabunga: 1954, Amer.Eng., 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: early 13c., from O.Fr. coart, from coe "tail," from L. coda, dialectal variant of cauda "tail," 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 O.Fr. versions of "Reynard the Fox." As a surname (attested from 1255) it represents O.E. cuhyrde "cow-herd."
"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]
An O.E. word for "cowardly" was earg, which also meant "slothful."
cowardice: c.1300, from O.Fr. couardise (13c.), from couard (see coward).
cowardly: early 14c. (adv.); 1550s (adj.), from coward (q.v.). The adv. is much older than the adj.
"Yit had I levir do what I may Than here to dye thus cowerdelye" ["Le Morte d'Arthur," c.1450]
cowboy: 1725, "boy who tends to cows," from cow + boy. Sense in Western U.S. is from 1849; fig. use by 1942 for "brash and reckless young man" (as an adj. meaning "reckless," from 1920s). Cowhand is first attested 1852 in Amer.Eng. Cowpoke (1881) was originally restricted to the cowboys who prodded cattle onto railroad cars with long poles.
cower: c.1300, probably from M.L.G. *kuren "lie in wait," or similar Scand. words meaning "to squat" and "to doze." Thus unrelated to coward.
cowl: O.E. cule, from earlier cugele, from L.L. cuculla "monk's cowl," var. of L. cucullus "hood," of uncertain origin.
cowlick: 1590s, from cow + lick.
coworker: also co-worker, 1640s, from co- + worker.
Cowper's gland: 1738, so called because discovered by anatomist William Cowper (1666-1709); see Cooper.
cowrie: 1662, from Hindi and Urdu kauri, from Mahrati kavadi, from Skt. kaparda, perhaps related to Tamil kotu "shell."
cowslip: O.E. cu-slyppe, apparently from cu "cow" + slyppe "slop, slobber, dung."
Cox: surname, from early 16c., earlier Cocks (c.1300), in many cases from cock (n.1), which apparently was used as a personal name in O.E., 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, or Welsh coch "red."
coxcomb: 1560s, from cokkes comb (see cockscomb).
coxswain: 1327, from cock "ship's boat" (from O.Fr. coque "canoe") + swain "boy," from O.N. sveinn "boy, servant."
coy: early 14c., from O.Fr. coi, earlier quei "quiet, still," ultimately from L. quietus "resting, at rest" (see quiet). Meaning "shy" emerged 14c. Meaning "unwilling to commit" is 1961.
coyote: 1759, Amer.Eng., from Mexican Sp., from Nahuatl coyotl.
coz: 1550s, familiar abbreviation of cousin.
coze (v.): to chat, 1828, perhaps from Fr. causer.
cozen: 1561, perhaps from Fr. cousiner "cheat on pretext of being a cousin;" or from M.E. cosyn "fraud, trickery" (1453), perhaps related to O.Fr. coçon "dealer," from L. cocionem "horse dealer."
cozy: 1709, colsie, Scottish dialect, perhaps of Scand. origin (cf. Norw. kose seg "be cozy"). In Britain, usually cosy.
cpr: by 1979, abbreviation of cardiopulmonary resuscitation.
cpu: by 1970, abbreviation of central processing unit.
crab: O.E. crabba, from a general Gmc. root (cf. Low Ger. krabben "to scratch, claw"). The constellation name is attested in Eng. from c.1000; the Crab Nebula (1868), however, is in Taurus, and is so called for its shape. Crab "fruit of the wild apple tree" (early 15c.) may be from unrelated Scandinavian scrab, of obscure origin. The combination of "bad-tempered, combative" and "sour" in the two words naturally yielded a meaning of "complain irritably," which is pre-1400. Crabgrass is c.1600, originally a marine grass of salt marshes; modern meaning is from 1743.
crabby: 1520s, in obs. sense "crooked, gnarled, rough," from extended sense of crab. Meaning "disagreeable, sour, peevish" is attested from 1776, Amer.Eng. Both senses were found earlier in crabbed (c.1510 and c.1300 respectively).
crack: O.E. cracian "make a sharp noise," from P.Gmc. *krakojan, probably onomatopoeic. The noun meaning "split, opening," is 14c. Meaning "try, attempt" first attested 1836, probably a hunting metaphor, from slang sense of "fire a gun." Meaning "rock cocaine" is first attested 1985. Cracked "mentally unsound" is 17c. (though the equivalent Gk. word was used in this sense by Aristophanes), while crack as in "top-notch, superior" is slang from 1793. Crackpot "pretentious, worthless person" dates from 1883. The superstition that it is bad luck to step on sidewalk cracks has been traced to c.1890.
crackdown: also crack down; 1935 (n.), 1940 (v.), from crack + down.
cracker: mid-15c., "hard wafer," but the specific application to a thin, crisp biscuit is 1739. Cracker-barrel (adj.) "emblematic of down-home ways and views" is from 1877. Cracker, Southern U.S. derogatory term for "poor, white trash" (1766), is from mid-15c. crack "to boast" (e.g. not what it's cracked up to be), originally a Scottish word. Especially of Georgians by 1808, though often extended to residents of northern Florida.
"I should explain to your Lordship what is meant by crackers; a name they have got from being great boasters; they are a lawless set of rascalls on the frontiers of Virginia, Maryland, the Carolinas and Georgia, who often change their places of abode." [1766, G. Cochrane]
cracker-jack: also crackerjack, "something excellent," 1895, U.S. colloquialism, apparently a fanciful construction. The caramel-coated popcorn-and-peanuts confection was said to have been introduced at the World's Columbian Exposition (1893). Supposedly a salesman gave it the name when he tasted some and said, "That's a cracker-jack," using the then-popular expression. The name was trademarked 1896. The "Prize in Every Box" was introduced 1912.
crackhead: slang, "crack cocaine addict," by 1986, from crack (in the drug slang sense) + head. In earlier slang, crack-headed meant "crazy" (1796), from the literal sense of crack.
crackle (v.): c.1560, crackelen, frequentative of cracken "to crack." The noun is recorded from 1833.
crackpot: 1883, probably from pot in a slang sense of "head." Cf. crack-brain "crazy fellow" (c.1570).
cradle: O.E. cradol "little bed," from P.Gmc. *kradulas "basket." Cat's cradle is from 1768. Cradle-snatching "amorous pursuit of younger person" is 1925, U.S. slang.
craft: O.E. cræft "power, strength, might," from P.Gmc. *krab-/*kraf-. Sense shifted to "skill, art" (via a notion of "mental power"), which led to the n. meaning of "trade." Use for "small boat" is first recorded 1671, probably from some nautical sense of "vessels of small craft," referring either to the trade they did or the seamanship they required.
craftsman: mid-14c., craftes man, from craft + man. Written as one word from late 14c. Related: Craftsmanship (1650s).
crafty: O.E. cræftig "strong, powerful," later "skillful," degenerating by c.1200 to "cunning, sly."
crag: c.1300, probably from a Celtic source akin to O.Ir. crec "rock," and carrac "cliff," and Manx creg.
craggy: mid-15c., from crag.
cram: O.E. crammian "press something into something else," from P.Gmc. base *kram-/*krem-. Meaning "study intensely for an exam" is British student slang first recorded 1803.
cramp (n.): "muscle contraction," late 14c., from O.Fr. crampe, from a Frankish word (cf. O.H.G. krapmhe "cramp, spasm," related to kramph "bent, crooked"). The same P.Gmc. root yielded M.Du. crampe, M.L.G. krampe, one of which gave Eng. cramp "a metal bar bent at both ends" (c.1500), which yielded a metaphoric sense (first recorded 1719) of "something that confines or hinders." Writer's cramp is first attested 1853.
cranberry: 1647, Amer.Eng. adaptation of Low Ger. kraanbere, from kraan "crane" + M.L.G. bere "berry," perhaps from a resemblance between the plants' stamens and the beaks of cranes. Ger. and Du. settlers in the New World apparently recognized the similarity between the European berries (Vaccinium oxycoccos) and the larger N.Amer. variety (V. macrocarpum) and transferred the name. In England, they were marshwhort or fenberries, but the N.Amer. berries, and the name, were brought over late 17c. The native Algonquian name for the plant is represented by W.Abenai popokwa.
crane: O.E. cran "large wading bird," from PIE *ger- (cf. Gk. geranos, Welsh garan, Lith. garnys "heron, stork"), perhaps echoic of its cry. Metaphoric use for "machine with a long arm" is first attested 1299. Verb meaning "to stretch (the neck)" is from 1799.
cranial: 1800, from Mod.L. cranium, from Gk. kranion "skull" (see cranium) + -al (1).
craniotomy: 1855, from Mod.L., from Gk. kranion "skull" (see cranium) + connecting element -o- + -tomy.
cranium: 1540s, from M.L. cranium, from Gk. kranion "skull," related to kara "head." Strictly, the bones which enclose the brain.
crank: O.E. cranc- preserved only in crancstæf "a weaver's instrument," from P.Gmc. base *krank-, and related to crincan "to bend, yield." Eng. retains the literal sense of the ancient root, while Ger. and Du. krank "sick," formerly "weak, small," is a figurative use. The sense of "an eccentric person," especially one who is irrationally fixated, is first recorded 1833, said to be from the crank of a barrel organ, which makes it play the same tune over and over, but more likely a back-formation from cranky "cross-tempered, irritable" (1821), and evolving from earlier senses of "a twist or fanciful turn of speech" (1594) or "inaccessible hole or crevice" (1562). Popularized 1881 when it was applied to Horace Greeley during Guiteau's trial. The verb meaning "turning a crank" is first attested 1908, with reference to automobile engines.
crankshaft: 1854, from crank + shaft. The basic form of the mechanism appears to date from Roman times.
cranny: c.1440, supposedly from M.Fr. cran "notch, fissure," from crener "to notch, split," from M.L. crenare, prob. from L. cernere "to separate, sift" (see crisis). But OED casts doubt on this derivation.
crap: "defecate" 1846 (v.), 1898 (n.), from one of a cluster of words generally applied to things cast off or discarded (e.g. "weeds growing among corn" (1425), "residue from renderings" (1490s), 18c. underworld slang for "money," and in Shropshire, "dregs of beer or ale"), all probably from M.E. crappe "grain that was trodden underfoot in a barn, chaff" (c.1440), from M.Fr. crape "siftings," from O.Fr. crappe, from M.L. crappa, crapinum "chaff." Sense of "rubbish, nonsense" also first recorded 1898. Despite folk etymology insistence, not from Thomas Crapper (1837-1910) who was, however, a busy plumber and may have had some minor role in the development of modern toilets. The name Crapper is a northern form of Cropper (attested from 1221), an occupational surname, obviously, but the exact reference is unclear.