coeliac (adj.) Look up coeliac at Dictionary.com
1660s, from Latin coeliacus, from Greek koiliakos "pertaining to the bowels," also "pain in the bowels," from koilia "bowels, abdominal cavity, intestines, tripe" from koilos "hollow," from PIE root *keue- "to swell; vault, hole" (see cumulus).
coelomate (n.) Look up coelomate at Dictionary.com
1883, from Coelomata (1877), from Modern Latin neuter plural of coelomatus, from Greek koilomat- "hollow, cavity," from PIE root *kel- (1) "to cover, conceal, save."
coeno- Look up coeno- at Dictionary.com
word-forming element meaning "common," Latinized from Greek koinos "common, public, shared, general, ordinary," from PIE *kom "beside, near, by, with" (see com-).
coequal (adj.) Look up coequal at Dictionary.com
late 14c.; see co- + equal (adj.).
coerce (v.) Look up coerce at Dictionary.com
mid-15c., cohercen, from Middle French cohercer, from Latin coercere "to control, restrain, shut up together," from com- "together" (see co-) + arcere "to enclose, confine, contain, ward off," from PIE *ark- "to hold, contain, guard" (see arcane). Related: Coerced; coercing. No record of the word between late 15c. and mid-17c.; its reappearance 1650s is perhaps a back-formation from coercion.
coercion (n.) Look up coercion at Dictionary.com
early 15c., from Old French cohercion (Modern French coercion), from Medieval Latin coercionem, from Latin coerctionem, earlier coercitionem, noun of action from past participle stem of coercere (see coerce).
coercive (adj.) Look up coercive at Dictionary.com
c. 1600, from coerce + -ive. Form coercitive (attested from 1630s) is more true to Latin.
coetaneous (adj.) Look up coetaneous at Dictionary.com
"having the same age," c. 1600, from Late Latin coaetanus "one of the same age," from assimilated form of Latin com "with, together with" (see com-) + aetat- "age" (see age (n.)) + adjectival suffix -aneus.
coeval (adj.) Look up coeval at Dictionary.com
"having the same age," formed in English early 17c. from Late Latin coaevus, from assimilated form of Latin com "with, together" (see com-) + aevum "an age" (see eon). As a noun from c. 1600.
coevolution (n.) Look up coevolution at Dictionary.com
also co-evolution, 1965, from co- + evolution; supposedly introduced by Paul Ehrlich and Peter Raven in a study of the relationship between caterpillars and plants.
coexist (v.) Look up coexist at Dictionary.com
1670s, from co- + exist. Of political/economic systems (especially with reference to communism and the West) from 1931. Related: Coexisted; coexisting.
coexistence (n.) Look up coexistence at Dictionary.com
also co-existence, mid-15c., "joint existence;" see co- + existence. As "peaceful relations between states of different ideologies," 1954, a Cold War term.
coextensive (adj.) Look up coextensive at Dictionary.com
1771, from co- + extensive.
coffee (n.) Look up coffee at Dictionary.com
c. 1600, from Italian caffe, from Turkish kahveh, from Arabic qahwah "coffee," said originally to have meant "wine," but perhaps rather from Kaffa region of Ethiopia, a home of the plant (coffee in Kaffa is called buno, which was borrowed into Arabic as bunn "raw coffee"). Much initial diversity of spelling, including chaoua.

Yemen was the first great coffee exporter and to protect its trade decreed that no living plant could leave the country. In 16c., a Muslim pilgrim brought some coffee beans from Yemen and raised them in India. Appeared in Europe (from Arabia) c. 1515-1519. Introduced to England by 1650, and by 1675 the country had more than 3,000 coffee houses. Coffee plantations established in Brazil 1727. Meaning "a light meal at which coffee is served" is from 1774. Coffee break attested from 1952, at first often in glossy magazine advertisements by the Pan-American Coffee Bureau. Coffee pot from 1705.
Did you drink a cup of coffee on company time this morning? Chances are that you did--for the midmorning coffee break is rapidly becoming a standard fixture in American offices and factories. ["The Kiplinger Magazine," March 1952]
coffer (n.) Look up coffer at Dictionary.com
mid-13c., from Old French cofre "a chest" (12c., Modern French coffre), from Latin cophinus "basket" (see coffin).
coffin (n.) Look up coffin at Dictionary.com
early 14c., "chest or box for valuables," from Old French cofin "sarcophagus," earlier "basket, coffer" (12c., Modern French coffin), from Latin cophinus "basket, hamper" (source of Italian cafano, Spanish cuebano "basket"), from Greek kophinos "a basket," which is of uncertain origin.

Funeral sense in English is 1520s; before that it was the literal Latin one and had also a meaning of "pie crust" (late 14c.). Meaning "vehicle regarded as unsafe" is from 1830s. Coffin nail "cigarette" is slang from 1880; nail in (one's) coffin "thing that contributes to one's death" is from 1792.
cog (n.) Look up cog at Dictionary.com
c. 1300, "cog wheel;" late 14c., "tooth on a wheel," probably a borrowing from a Scandinavian language (compare Norwegian kugg "cog") and cognate with Middle High German kugel "ball."
cogency (n.) Look up cogency at Dictionary.com
1680s, from cogent + -cy.
cogenial (adj.) Look up cogenial at Dictionary.com
1774, variant of congenial.
cogent (adj.) Look up cogent at Dictionary.com
1650s, from French cogent "necessary, urgent" (14c.), from Latin cogentem (nominative cogens), present participle of cogere "to curdle; to compel; to collect," literally "to drive together," from com- "together" (see co-) + agere "to set in motion, drive, drive forward; to do, perform" (from PIE root *ag- "to drive, draw out or forth, move").
cogitate (v.) Look up cogitate at Dictionary.com
late 16c., from Latin cogitatus, past participle of cogitare "to think" (see cogitation). Related: Cogitated; cogitating.
cogitation (n.) Look up cogitation at Dictionary.com
c. 1200, "thought, idea, notion," from Old French cogitacion "thought, consideration, reflection," from Latin cogitationem (nominative cogitatio), noun of action from past participle stem of cogitare "to think, reflect, consider, turn over in the mind," apparently from co-agitare, from com- "together" (see co-) + agitare, here in a sense of "to turn over in the mind," literally "to put in constant motion, drive, impel," frequentative of agere "to move, drive" (from PIE root *ag- "to drive, draw out or forth, move").
cogitative (adj.) Look up cogitative at Dictionary.com
late 15c., from Old French cogitatif (14c.), from Medieval Latin cogitativus, from Latin cogitare "to think" (see cogitation).
cognac (n.) Look up cognac at Dictionary.com
1590s, Coniacke, "wine produced in Cognac," the region in western France. The sense of "brandy" is 1755, shortened from 17c. cognac brandy, which was distilled from cognac wine. The place name is from Medieval Latin Comniacum, from the personal name Cominius and the Gallo-Roman suffix -acum.
cognate (adj.) Look up cognate at Dictionary.com
1640s, from Latin cognatus "of common descent," from com- "together" (see co-) + gnatus, past participle of gnasci, older form of nasci "to be born" (from PIE root *gene- "give birth, beget"). Words that are cognates are cousins, not siblings. As a noun, from 1754.
cognisance (n.) Look up cognisance at Dictionary.com
alternative spelling of cognizance (q.v.); also see -ize.
cognisant (adj.) Look up cognisant at Dictionary.com
alternative spelling of cognizant (q.v.); also see -ize.
cognition (n.) Look up cognition at Dictionary.com
mid-15c., "ability to comprehend," from Latin cognitionem (nominative cognitio) "a getting to know, acquaintance, knowledge," noun of action from past participle stem of cognoscere "to get to know, recognize" (see cognizance).
cognitive (adv.) Look up cognitive at Dictionary.com
1580s, from Latin cognit-, past participle stem of cognoscere "to get to know, recognize" (see cognizance) + -ive. Taken over by psychologists and sociologists after c. 1940. Related: Cognitively.
cognitive dissonance (n.) Look up cognitive dissonance at Dictionary.com
1957, developed and apparently coined by U.S. social psychologist Leon Festinger (1919-1989).
cognizable (adj.) Look up cognizable at Dictionary.com
1670s, "capable of being known," also "liable to be tried in a given court or jurisdiction," from stem of cognizance + -able.
cognizance (n.) Look up cognizance at Dictionary.com
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," from PIE root *gno- "to know." 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.) Look up cognizant at Dictionary.com
1820, back-formation from cognizance.
cognize (v.) Look up cognize at Dictionary.com
1650s, back-formation from cognizance. Related: Cognized; cognizing.
cognomen (n.) Look up cognomen at Dictionary.com
1809, from assimilated form of Latin com "with, together" (see com-) + (g)nomen "name" (see name (n.)). Third or family name of a Roman citizen (Caius Julius Cæsar).
cognoscence (n.) Look up cognoscence at Dictionary.com
mid-15c., from Latin cognoscere "to get to know, recognize" (see cognizance).
cognoscente (n.) Look up cognoscente at Dictionary.com
"connoisseur," 1778, from Italian cognoscente, Latinized from conoscente "connoisseur," literally "knowing man," from Latin cognoscentum (nominative cognoscens), present participle of cognoscere "to get to know, recognize" (see cognizance).
cognoscenti (n.) Look up cognoscenti at Dictionary.com
plural of cognoscente (q.v.).
cohabit (v.) Look up cohabit at Dictionary.com
euphemism since 1530s to describe a couple living together without benefit of marriage; back-formation from cohabitation. Related: Cohabited; cohabiting.
cohabitate (v.) Look up cohabitate at Dictionary.com
1630s, from Late Latin cohabitatus, past participle of cohabitare (see cohabitation). Related: Cohabitated; cohabitating.
cohabitation (n.) Look up cohabitation at Dictionary.com
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, inhabit, dwell," frequentative of habere "to have, to hold, possess" (from PIE root *ghabh- "to give or receive").
Cohen Look up Cohen at Dictionary.com
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.) Look up cohere at Dictionary.com
1590s, from Latin cohaerere "to cleave together," in transferred use, "be coherent or consistent," from com- "together" (see co-) + haerere "to adhere, stick" (see hesitation). Related: Cohered; cohering.
coherence (n.) Look up coherence at Dictionary.com
late 16c., from Middle French cohérence (16c.), from Latin cohaerentia, abstract noun from cohaerentem (see coherent). Related: Coherency.
coherent (adj.) Look up coherent at Dictionary.com
1550s, from Middle French cohérent (16c.), from Latin cohaerentem (nominative cohaerens), present participle of cohaerere "cohere," from com- "together" (see co-) + haerere "to adhere, stick" (see hesitation).
cohesion (n.) Look up cohesion at Dictionary.com
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.) Look up cohesive at Dictionary.com
c. 1730 (implied in cohesiveness), from Latin cohaes-, past participle stem of cohaerere (see cohere) + -ive. Related: Cohesively.
cohort (n.) Look up cohort at Dictionary.com
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 PIE root *gher- (1) "to grasp, enclose." Sense of "accomplice" is first recorded 1952, American English, from meaning "group united in common cause" (1719).
coif (v.) Look up coif at Dictionary.com
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.
coif (n.) Look up coif at Dictionary.com
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 (compare Old High German kupphia, Middle High German kupfe "cap").