Online Etymology Dictionary

cognizable (adj.): 1670s, "capable of being known," also "liable to be tried in a given court or jurisdiction," from stem of cognizance + -able.
cognizance (n.): mid-14c., from Anglo-French conysance "recognition," later, "knowledge," from Old French conoissance "acquaintance, recognition; knowledge, wisdom" (Modern French connaissance), from past participle of conoistre "to know," from Latin cognoscere "to get to know, recognize," from com- "together" (see co-) + gnoscere "to know" (see notice). The -g- was restored in English spelling 15c. and has gradually affected the pronunciation, which was always "con-." The old pronunciation lingered longest in legal use.
cognizant (adj.): 1820, back-formation from cognizance.
cognize (v.): 1650s, back-formation from cognizance. Related: Cognized; cognizing.
cognomen (n.): 1809, from Latin com- "with" (see co-) + (g)nomen "name" (see name (n.)). Third or family name of a Roman citizen (Caius Julius Cæsar).
cognoscence (n.): mid-15c., from Latin cognoscere "to know" (see cognizance).
cognoscente (n.): "connoisseur," 1778, from Italian cognoscente, Latinized from conoscente "connoisseur," literally "knowing man," from Latin cognoscentum (nominative cognoscens), present participle of cognoscere "to know" (see cognizance).
cognoscenti (n.): plural of cognoscente (q.v.).
cohabit (v.): euphemism since 1530s to describe a couple living together without benefit of marriage; back-formation from cohabitation. Related: Cohabited; cohabiting.
cohabitate (v.): 1630s, from Late Latin cohabitatus, past participle of cohabitare (see cohabitation). Related: Cohabitated; cohabitating.
cohabitation (n.): mid-15c., "action or state of living together (especially as husband and wife)," from Middle French cohabitation (Old French cohabitacion "cohabitation, sexual intercourse"), from Late Latin cohabitationem (nominative cohabitatio), noun of action from past participle stem of cohabitare "to dwell together," from co- "with, together" (see co-) + habitare "to live, dwell" (see habitat).
Cohen: Jewish surname indicating priestly descent, from Hebrew kohen "priest," from base of kihen "he acted as priest," related to Arabic kahana "he divined, prophesied."
cohere (v.): 1590s, from Latin cohaerere "to cleave together," in transferred use, "be coherent or consistent," from com- "together" (see co-) + haerere "to stick" (see hesitation). Related: Cohered; cohering.
coherence (n.): late 16c., from Middle French cohérence (16c.), from Latin cohaerentia, noun of state from cohaerentem (see coherent). Related: Coherency.
coherent (adj.): 1550s, from Middle French cohérent (16c.), from Latin cohaerentem (nominative cohaerens), present participle of cohaerere "cohere," from com- "together" (see co-) + haerere "to stick" (see hesitation).
cohesion (n.): 1670s, from French cohésion, from Latin cohaesionem (nominative cohaesio) "a sticking together," noun of action from past participle stem of cohaerere "to stick together" (see cohere).
cohesive (adj.): c.1730 (implied in cohesiveness), from Latin cohaes-, past participle stem of cohaerere (see cohere) + -ive. Related: Cohesively.
cohort (n.): early 15c., "company of soldiers," from Middle French cohorte (14c.) and directly from Latin cohortem (nominative cohors) "enclosure," meaning extended to "infantry company" in Roman army (a tenth part of a legion) through notion of "enclosed group, retinue," from com- "with" (see co-) + root akin to hortus "garden," from PIE *ghr-ti-, from root *gher- "to grasp, enclose" (see yard (n.1)). Sense of "accomplice" is first recorded 1952, American English, from meaning "group united in common cause" (1719).
coif (n.): late 13c., "close-fitting cap," from Old French coife "skull-cap, cap worn under a helmet, headgear" (12c., Modern French coiffe), from Late Latin coifa "a cap, hood" (source of Italian cuffia, Spanish cofia, escofia), of West Germanic origin (cf. Old High German kupphia, Middle High German kupfe "cap").
coif (v.): mid-15c., "to cover with a cap," from Middle French coiffer, from Old French coife (see coif (n.)); sense of "to arrange the hair" is attested in English from 1835. Related: Coifed; coifing.
coiffeur (n.): 1847, from French coiffeur "hairdresser," from coiffer "to dress hair," from Old French coife, originally, "inner part of the helmet" (see coif (n.)). A woman hairdresser would be properly a coiffeuse.
coiffure (n.): "style or fashion of wearing the hair," 1630s, from French coiffure, from coiffer (see coiffeur).
coign (n.): archaic spelling of quoin (q.v.), surviving only in Shakespeare's coign of vantage ("Macbeth" I.vi.), popularized by Sir Walter Scott, properly "a projecting corner" (for observation).
coil (v.): "to wind," 1610s, from Middle French coillir "to gather, pick," from Latin colligere "to gather together" (see collect). Meaning specialized perhaps in nautical usage. Related: Coiled; coiling.
coil (n.): 1620s, from coil (v.). Related: Coils.
coin (n.): c.1300, "a wedge," from Old French coing (12c.) "a wedge; stamp; piece of money; corner, angle," from Latin cuneus "a wedge." The die for stamping metal was wedge-shaped, and the English word came to mean "thing stamped, a piece of money" by late 14c. (a sense that already had developed in French). Cf. quoin, which split off from this word 16c. Modern French coin is "corner, angle, nook."
coin (v.): "to coin money," mid-14c., from coin (n.). Related: Coined; coining. To coin a phrase is late 16c. A Middle English word for minter was coin-smiter.
coinage (n.): late 14c., "currency, money," from Old French coignage, from coignier "to coin" (see coin (n.)). Meaning "act or proces of coining money" is from early 15c.; sense "deliberate formation of a new word" is from 1690s, from a general sense of "something invented" (c.1600).
coincide (v.): 1715, from French coincider (14c.), from Medieval Latin coincidere (in astrological use), literally "to fall upon together," from Latin com- "together" (see co-) + incidere "to fall upon" (in- "upon + cadere "to fall;" see case (n.1)). Related: Coincided; coinciding.
coincidence (n.): c.1600, "exact correspondence," from French coincidence, from coincider (see coincide). Meaning "a concurrence of events with no apparent connection" is from 1680s.
coincident (adj.): late 16c., from French coincident, from coincider (see coincide).
coincidental (adj.): c.1800, from coincident + -al (1).
coincidentally (adv.): 1837, from coincidental + -ly (2).
coincidently: 1620s, from coincident + -ly (2).
Cointreau (n.): orange-flavored liqueur, named for founders Adolphe and Edouard-Jean Cointreau, brothers from Angers, France, who set up Cointreau Distillery in 1849. The orange liqueur dates from 1875.
coir (n.): "prepared coconut fiber," 1580s, from Malayalam kayar "cord," from kayaru "to be twisted."
coit (n.): "coition," 1670s, from Latin coitus "going together," also "coition," from coire "to go together" (see coitus).
coition (n.): 1540s, "going together, coming together," from Late Latin coitionem (nominative coitio), noun of action from coitus, past participle of coire "to go together, come together" (see coitus). Meaning "sexual copulation" is attested in English from 1610s.
coitus (n.): "copulation," 1713, scientific Latin, from Latin coitus "a meeting together; sexual union," past participle of coire, from com- "together" (see co-) + ire "come, go," (see ion). In Middle English as coite (early 15c.). Used in English in general senses of "meeting, uniting," and also of magnetic force, planetary conjunction, etc., before sexual sense came to predominate.
coitus interruptus (n.): 1900, first attested in Havelock Ellis.
cojones (n.): "courage," literally "balls," 1932, from Spanish cojon "testicle," from Latin coleus, culleus (source of Italian coglione), literally "a leather sack," related to Greek koleos "sheath, scabbard (see cell). In English, first attested in Hemingway.
coke (n.2): shortened form of cocaine, 1908, American English.
coke (n.1): "residue of fuel," 1690s, northern English dialect, perhaps a variant of Middle English colke "core, charcoal" (c.1400), itself possibly related to -colc, an Old English word for "pit," which perhaps would give it a sense of "what is left in the pit after a fire."
Coke: soft drink, 1909, shortening of brand name Coca-Cola.
col-: form of Latin com- before stems beginning in -l- (see com-).
cola (n.): 1795, genus of trees native to west Africa and introduced in New World tropics, Latinized form of a West African name of the tree (cf. Temne kola, Mandingo kolo). Meaning "carbonated soft drink" is 1920, short for Coca-Cola, Pepsi-Cola.
colander (n.): mid-14c., coloundour, probably altered from Medieval Latin colatorium "strainer" (with parasitic -n-) from Latin colatus, past participle of colare "to strain," from colum "sieve, strainer, wicker fishing net," of uncertain origin. Cognate with French couloir, Spanish colador, Italian colatojo.
cold (adj.): Old English cald (Anglian), ceald (West Saxon) "cold, cool" (adj.), "coldness," from Proto-Germanic *kaldaz (cf. Old Frisian and Old Saxon kald, Old High German and German kalt, Old Norse kaldr, Gothic kalds "cold"), possibly a past participle adjective of *kal-/*kol-, from PIE root *gel-/*gol- "cold" (cf. Latin gelare "to freeze," gelu "frost," glacies "ice").

Meaning "not strong" (in reference to scent) is 1590s, from hunting. Cold front in weather is from 1921. Cold-call in the sales pitch sense first recorded 1972. Japanese has two words for "cold:" samui for coldness in the atmosphere or environment; tsumetai for things which are cold to touch, and also in the figurative sense, with reference to personalities, behaviors, etc.
cold (n.): c.1300, "coldness," from cold (adj.). Sense in common cold is 1530s, from symptoms resembling those of exposure to cold; cf. earlier senses "indisposition caused by exposure to cold" (early 14c.); "discomfort caused by cold" (c.1300).
cold blooded (adj.): also cold-blooded; 1590s, of persons, "without emotion, unfeeling;" of actions, from 1828. The phrase refers to the old notion that blood temperature rose with excitement. In the literal sense, of reptiles, etc., from c.1600.