convergence (n.) Look up convergence at Dictionary.com
1713, from converge + -ence. Related: Convergent. Convergent evolution was in use among biologists by 1890.
conversant (adj.) Look up conversant at Dictionary.com
late 14c., from Old French conversant, present participle of converser (see converse (v.)).
conversate (v.) Look up conversate at Dictionary.com
by 1994, apparently a back-formation from conversation or an elaboration of converse. According to some, from U.S. black English.
conversation (n.) Look up conversation at Dictionary.com
mid-14c., "living together, having dealings with others," also "manner of conducting oneself in the world;" from Old French conversation, from Latin conversationem (nominative conversatio) "act of living with," noun of action from past participle stem of conversari "to live with, keep company with," literally "turn about with," from Latin com- "with" (see com-) + vertare, frequentative of vertere (see versus).

Specific sense of "talk" is 1570s. Used as a synonym for "sexual intercourse" from at least 1511, hence criminal conversation, legal term for adultery from late 18c. Related: Conversationalist; conversationist.
conversational (adj.) Look up conversational at Dictionary.com
1779, from conversation + -al (1).
converse (v.) Look up converse at Dictionary.com
"to communicate (with)," 1590s; earlier "to move about, live, dwell" (mid-14c.), from Old French converser "to talk" (12c.), from Latin conversari (see conversation). Related: Conversed; conversing.
converse (adj.) Look up converse at Dictionary.com
"exact opposite," 1560s, from Latin conversus "turn around," past participle of convertere "to turn about" (see convert). Originally mathematical. The noun is attested from 1550s in mathematics. Related: Conversely.
conversion (n.) Look up conversion at Dictionary.com
mid-14c., originally of religion, from French conversion, from Latin conversionem (nominative conversatio), noun of action from past participle stem of convertere (see convert (v.)). General sense of "transformation" is early 15c. Of buildings, from 1921. Conversion disorder "hysteria" (attested from 1946 but said to have been coined by Freud) was in DSM-IV (1994).
convert (v.) Look up convert at Dictionary.com
c.1300, from Old French convertir, from Vulgar Latin *convertire, from Latin convertere "turn around, transform," from com- "together" (see com-) + vertere "to turn" (see versus). Originally in the religious sense. The Latin word is glossed in Old English by gecyrren, from cierran "to turn, return." Related: Converted; converting.
convert (n.) Look up convert at Dictionary.com
1560s, from convert (v.). Earlier was convers (early 14c.).
converter (n.) Look up converter at Dictionary.com
1530s, agent noun from convert (v.). Of machinery, from 1867.
convertible (adj.) Look up convertible at Dictionary.com
late 14c., from Old French convertible (13c.), from Late Latin convertibilis "changeable," from Latin convertere (see convert (v.)). The noun is recorded from 1610s; meaning "automobile with a fold-down top" is from 1916.
convex (adj.) Look up convex at Dictionary.com
1570s, from Middle French convexe, from Latin convexus "vaulted, arched," past participle of convehere "to bring together," from com- "together," or "thoroughly" (see com-) + vehere "to bring" (see vehicle). Possibly from the idea of vaults carried together to meet at the point of a roof. Related: Convexity. Convex lens is from 1822.
convey (v.) Look up convey at Dictionary.com
c.1300, "to go along with;" late 14c., "to carry, transport;" from Anglo-French conveier, from Old French convoier "to escort" (Modern French convoyer), from Vulgar Latin *conviare "to accompany on the way," from Latin com- "together" (see com-) + via "way, road" (see via). It was a euphemism for "steal" 15c.-17c., which helped broaden its meaning. Related: Conveyed; conveying.
conveyance (n.) Look up conveyance at Dictionary.com
mid-15c., "act of conveying," from convey + -ance. Meaning "document by which something is legally conveyed" is from 1570s; sense "means of transportation" is attested from 1590s. Related: Conveyanced; conveyancing.
conveyer (n.) Look up conveyer at Dictionary.com
1510s, agent noun from convey. Latinate form conveyor is later (1640s).
convict (v.) Look up convict at Dictionary.com
mid-14c., from Latin convictus, past participle of convincere "to 'overcome' in argument" (see convince). Replaced Old English verb oferstælan. Related: Convicted; convicting.
convict (n.) Look up convict at Dictionary.com
late 15c., from convict (v). Slang shortening con is from 1893.
conviction (n.) Look up conviction at Dictionary.com
mid-15c., "the proving of guilt," from Late Latin convictionem (nominative convictio) "proof, refutation," noun of action from past participle stem of convincere (see convince). Meaning "mental state of being convinced" is from 1690s; that of "firm belief, a belief held as proven" is from 1841.
convictions (n.) Look up convictions at Dictionary.com
"those ideas which one believes to be true," 1883, plural of conviction.
convince (v.) Look up convince at Dictionary.com
1520s, "to overcome in argument," from Latin convincere "to overcome decisively," from com-, intensive prefix (see com-), + vincere "to conquer" (see victor). Meaning "to firmly persuade" is from c.1600. Related: Convinced; convincing; convincingly.
convival (adj.) Look up convival at Dictionary.com
1640s, from Latin convivalis, from conviva, from convivere (see convivial). Has been replaced in most uses by convivial.
convive (n.) Look up convive at Dictionary.com
1640s, from French convive, from Latin conviva "one who feasts with others," from convivere (see convivial). In mid-19c., also "woman 'who lives in the same house with a number of others.' "
convivial (adj.) Look up convivial at Dictionary.com
1660s, "pertaining to a feast," from Late Latin convivialis, from Latin convivium "a feast," from convivere "to carouse together," from com- "together" (see com-) + vivere "to live" (see vital). Meaning "sociable" is from 18c. Related: Conviviality.
convocate (v.) Look up convocate at Dictionary.com
mid-16c., from Latin convocatus, past participle of convocare (see convocation).
convocation (n.) Look up convocation at Dictionary.com
late 14c., "assembly of persons," from Old French convocation and directly from Latin convocationem (nominative convocatio), noun of action from past participle stem of convocare "to call together," from com- "together" (see com-) + vocare "to call," from vox "voice" (see voice (n.)). Related: Convocational.
convoke (v.) Look up convoke at Dictionary.com
1590s, from Middle French convoquer (14c.), from Latin convocare "to call together" (see convocation). Related: Convoked; convoking.
convolute (adj.) Look up convolute at Dictionary.com
"rolled up together," 1794, from Latin convolutus, past participle of convolvere (see convolution). The noun meaning "something convoluted" is from 1846.
convoluted (adj.) Look up convoluted at Dictionary.com
1811, past participle adjective from verb convolute (1690s), from Latin convolutus, past participle of convolvere (see convolution); or perhaps a back-formation from convolution. French has convoluté (18c.), in form a past participle adjective, without the verb.
convolution (n.) Look up convolution at Dictionary.com
1540s, from Latin convolutus, past participle of convolvere "to roll together," from com- "together" (see com-) + volvere "to roll" (see volvox).
convoy (n.) Look up convoy at Dictionary.com
early 16c., "the act of guiding or escorting for protection," from convoy (v.), late 14c., from Old French convoier, from Vulgar Latin *conviare, literally "go together on the road" (see convey). The meaning "train of ships or wagons carrying munitions or provisions in wartime under protection of escort" is from c.1600.
convulse (v.) Look up convulse at Dictionary.com
1640s, transitive; 1680s, intransitive; from Latin convulsus, past participle of convellere (transitive only) "to pull away, to pull this way and that, wrench," hence "to weaken, overthrow, destroy" (see convulsion). Related: Convulsed (1630s); convulsing.
convulsion (n.) Look up convulsion at Dictionary.com
1580s, from Latin convulsionem (nominative convulsio), noun of action from past participle stem of convellere "to tear loose," from com- "together" (see com-) + vellere "to pluck, pull violently" (see svelte).
convulsive (adj.) Look up convulsive at Dictionary.com
1610s, from French convulsif, from Medieval Latin *convulsivus, from convulsus, past participle of convellere (see convulse (v.)). Related: Convulsively.
cony (n.) Look up cony at Dictionary.com
see coney.
coo (v.) Look up coo at Dictionary.com
1660s, echoic of doves; the phrase to bill and coo is first recorded 1816. Related: Cooing. The noun is recorded from 1729.
cooch (n.) Look up cooch at Dictionary.com
"vagina," slang, c.2003, short for coochie.
coochie (n.) Look up coochie at Dictionary.com
"vagina," slang, by 1991, perhaps from hoochie-coochie, especially in the blues song "Hoochie Coochie Man" by Willie Dixon (1954), featuring a sexually suggestive phrase that traces at least to the 1893 World's Fair (see hoochy koochy).
cook (n.) Look up cook at Dictionary.com
Old English coc, from Vulgar Latin cocus "cook," from Latin coquus, from coquere "to cook, prepare food, ripen, digest, turn over in the mind" from PIE root *pekw- "to cook" (cognates: Oscan popina "kitchen," Sanskrit pakvah "cooked," Greek peptein, Lithuanian kepti "to bake, roast," Old Church Slavonic pecenu "roasted," Welsh poeth "cooked, baked, hot"). Germanic languages had no one native term for all types of cooking, and borrowed the Latin word (Old Saxon kok, Old High German choh, German Koch, Swedish kock).
There is the proverb, the more cooks the worse potage. [Gascoigne, 1575]
cook (v.) Look up cook at Dictionary.com
late 14c., from cook (n.); the figurative sense of "to manipulate, falsify, doctor" is from 1630s. Related: Cooked, cooking. To cook with gas is 1930s jive talk.
cookbook (n.) Look up cookbook at Dictionary.com
1809, from cook + book (n.). Earlier was cookery book (1630s).
cooker (n.) Look up cooker at Dictionary.com
type of stove, 1884, from cook (v.) + -er (1).
cookery (n.) Look up cookery at Dictionary.com
late 14c.; see cook (n.) + -ery.
cookie (n.) Look up cookie at Dictionary.com
1703, American English, from Dutch koekje "little cake," diminutive of koek "cake," from Middle Dutch koke (see cake (n.)). Slang application to persons attested since 1920. Phrase that's the way the cookie crumbles "that's the way things happen" is from 1957.
cookout (n.) Look up cookout at Dictionary.com
also cook-out, 1930, American English, from cook (v.) + out (adv.).
cooky (n.) Look up cooky at Dictionary.com
variant of cookie.
cool (adj.) Look up cool at Dictionary.com
Old English col "not warm" (but usually not as severe as cold), also, of persons, "unperturbed, undemonstrative," from Proto-Germanic *koluz (cognates: Middle Dutch coel, Dutch koel, Old High German kuoli, German kühl "cool," Old Norse kala "be cold"), from PIE root *gel- "cold, to freeze" (see cold (adj.)).

Applied since 1728 to large sums of money to give emphasis to amount. Meaning "calmly audacious" is from 1825. Slang use for "fashionable" is 1933, originally Black English; modern use as a general term of approval is from late 1940s, probably from bop talk and originally in reference to a style of jazz; said to have been popularized in jazz circles by tenor saxophonist Lester Young. Related: Coolly.
cool (n.) Look up cool at Dictionary.com
c.1400, "coldness, coolness," from cool (adj.). Meaning "one's self-control, composure" (the thing you either keep or lose) is from 1966.
cool (v.) Look up cool at Dictionary.com
Old English colian, "to lose warmth," also figuratively, "to lose ardor," from the root of cool (adj.). Meaning "to cause to lose warmth" is from late 14c. Related: Cooled; cooling.
coolant (n.) Look up coolant at Dictionary.com
"radiator fluid," 1930, from cool (adj.) + -ant.