Online Etymology Dictionary

conclusive (adj.): 1610s, "occurring at the end," from French conclusif, from Late Latin conclusivus, from conclus-, past participle stem of concludere (see conclude). Meaning "definitive, decisive, convincing" (putting an end to debate) is from 1640s. Related: Conclusiveness.
conclusively (adv.): 1550s, "in conclusion," from conclusive + -ly (2). Meaning "decisively" is recorded from 1748.
conclusory (adj.): 1846, "pertaining to a conclusion," from stem of conclusion + -ory. Probably coined because the secondary "decisive" sense had come to predominate in conclusive.
concoct (v.): 1530s, "to digest," from Latin concoctus, past participle of concoquere "to digest; to boil together, prepare; to consider well," from com- "together" (see com-) + coquere "to cook" (see cook (n.)). Meaning "to prepare an edible thing" is from 1670s. First expanded metaphorically beyond cooking 1792. Related: Concocted; concocting.
concoction (n.): 1530s, "digestion," from Latin concoctionem (nominative concoctio) "digestion," noun of action from past participle stem of concoquere (see concoct). Meaning "preparation of a medicinal potion" is from 1851; sense of "a made-up story" is from 1823.
concomitance (n.): 1520s, from Middle French concomitance, from Medieval Latin concomitantia, from Late Latin concomitantem (see concomitant). Related: Concomitancy.
concomitant (adj.): c. 1600, from French concomitant, from Late Latin concomitantem (nominative concomitans), present participle of concomitari "accompany, attend," from com- "with, together" (see com-) + comitari "join as a companion," from comes (genitive comitis) "companion" (see count (n.)).
concord (n.): early 14c., from Old French concorde (12c.) "concord, harmony, agreement, treaty," from Latin concordia "agreement, union," from concors (genitive concordis) "of the same mind," literally "hearts together," from com- "together" (see com-) + cor "heart," from PIE root *kerd- "heart" (see heart).
concordance (n.): late 14c., "alphabetical arrangement of all the words in a book" (especially the Bible), from Old French concordance (12c.) "agreement, harmony," from Late Latin concordantia, from concordantem (nominative concordans; see concord). Originally a citation of parallel passages. Literal meaning "fact of agreeing" attested in English from mid-15c.
concordant (adj.): late 15c. of persons, 1510s of things, 1550s of music, from French concordant, from Latin concordantem, present participle of concordare (see concord). Related: Concordantly.
concordat (n.): "agreement between church and state on a mutual matter," 1610s, from French concordat (16c.), from Medieval Latin concordatum, noun use of Latin concordatum, neuter past participle of concordare "to agree," from concors (genitive concordis) "of one mind" (see concord).
Concorde (n.): supersonic passenger airliner, operating from 1976 to 2003, from French concorde, literally "harmony, agreement" (see concord), reflecting the Anglo-French collaborative agreement that produced it.
concours (n.): from French concours (16c.) "assemblage of things brought together," also "contest" (see concourse). Usually in English in phrase concours d'elegance.
concourse (n.): late 14c., from Middle French concours, from Latin concursus "a running together," from past participle of concurrere (see concur). Originally "the flowing of a crowd of people;" sense of "open space in a built-up place" is American English, 1862.
concrete (adj.): late 14c., "actual, solid," from Latin concretus "condensed, hardened, thick, hard, stiff, curdled, congealed, clotted," figuratively "thick; dim," literally "grown together;" past participle of concrescere "to grow together," from com- "together" (see com-) + crescere "to grow" (see crescent). A logicians' term until meaning began to expand 1600s. Noun sense of "building material made from cement, etc." is first recorded 1834.
concrete poetry (n.): 1958, from terms coined independently in mid-1950s in Brazil (poesia concreta) and Germany (die konkrete Dichtung). Related: Concrete poem (1958).
concretion (n.): by 1670s, from French concrétion, from Latin concretionem (nominative concretio), from concretus (see concrete).
concretize (v.): 1884, from concrete + -ize. Concrete itself sometimes was used as a verb in various senses from 1630s.
concubinage (n.): late 14c., from Middle French concubinage, from concubin, from Latin concubina (see concubine).
concubine (n.): c. 1300, from Latin concubina (fem.), from concumbere "to lie with, to lie together, to cohabit," from com- "with" (see com-) + cubare "to lie down" (see cubicle). Recognized by law among polygamous peoples as "a secondary wife."
concupiscence (n.): mid-14c., from Latin concupiscentia "eager desire," from concupiscens, present participle of concupiscere, inceptive of concupere "to be very desirous of," from com-, intensive prefix (see com-), + cupere "to long for" (see cupidity). Used in Vulgate to translate Greek epithymia.
concupiscent (adj.): mid-15c., from Latin concupiscentem (nominative concupiscens), present participle of concupiscere "to long for, covet" (see concupiscence).
concur (v.): early 15c., "collide, clash in hostility," from Latin concurrere "to run together, assemble hurriedly; clash, fight," in transferred use, "to happen at the same time," from com- "together" (see com-) + currere "to run" (see current (adj.)). Sense of "to coincide, happen at the same time" is 1590s; that of "to agree in opinion" is 1580s in English.
concurrence (n.): early 15c., from Old French concurrence (14c.) or directly from Medieval Latin concurrentia "a running together," from concurrens, present participle of concurrere (see concur).
concurrent (adj.): late 14c., from Old French concurrent or directly from Latin concurrentem (nominative concurrens), present participle of concurrere (see concur). Related: Concurrency; concurrently. Concurrent jurisdiction is recorded from 1767.
concurring (adj.): 1590s, from present participle of concur. Concurring opinion is recorded from 1720.
concuss (v.): 1590s, "to shake violently," from Latin concuss-, past participle stem of concutere "to dash together, shake violently" (see concussion). Meaning "to give a concussion to the brain" is from 1680s. Related: Concussed; concussing; concussive.
concussion (n.): c. 1400, from Latin concussionem (nominative concussio) "a shaking," noun of action from past participle stem of concutere "shake violently," from com- "together" (see com-) + quatere "to shake" (see quash). Modern brain injury sense is from 1540s.
condemn (v.): early 14c., condempner "to blame, censure," from Old French condamner "to condemn" (11c.), from Latin condemnare "to sentence, doom, blame, disapprove," from com-, intensive prefix (see com-), + damnare "to harm, damage" (see damn). Replaced Old English fordeman. Related: Condemned; condemning.
condemnation (n.): late 14c., from Latin condemnationem (nominative condemnatio), noun of action from past participle stem of condemnare (see condemn).
condemnatory (adj.): late 16c., from Latin condemnat-, past participle stem of condemnare (see condemn) + -ory.
condemned (adj.): 1540s, "found guilty, at fault," past participle adjective from condemn. Of property, "found unfit for use," from 1798.
condensate (v.): 1550s, "to make dense," from condens-, past participle stem of Latin condensare (see condense) + -ate (2). Meaning "to become dense" is from c. 1600.
condensation (n.): c. 1600, "action of becoming more dense," from Latin condensationem (nominative condensatio), noun of action from condensare (see condense). Meaning "conversion of a gas to a liquid" is from 1610s.
condense (v.): early 15c., from Middle French condenser (14c.) or directly from Latin condensare "to make dense," from com-, intensive prefix (see com-), + densare "make thick," from densus "dense, thick, crowded," a word used of crowds, darkness, clouds, etc. (see dense).
condensed (adj.): c. 1600, "made more dense," past participle adjective from condense. Of literary works, from 1823. Condensed milk attested by 1863.
condenser (n.): 1680s, agent noun from condense. Given a wide variety of technical uses in late 18c. and 19c.
condescend (adj.): mid-14c., "to yield deferentially," from Old French condescendere (14c.) "to agree, consent, give in, yield," from Late Latin condescendere "to let oneself down," from Latin com- "together" (see com-) + descendere "descend" (see descend). Sense of "to sink willingly to equal terms with inferiors" is from mid-15c.
condescendence (n.): 1630s, from French condescendance, from condescendre, from Latin condescendere (see condescend).
condescending (adj.): 1707, present participle adjective from condescend. Originally in a positive sense (of God, the Savior, etc.) until late 18c. Related: Condescendingly (1650s).
condescension (n.): 1640s, from Late Latin condescensionem, noun of action from past participle stem of condescendere (see condescend).
condescent (n.): mid-15c., from condescend on model of descent.
condign (adj.): late 15c., "well-deserved," from Old French condigne "deserved, appropriate, equal in wealth," from Latin condignus "wholly worthy," from com- "together, altogether" (see com-) + dignus "worthy" (see dignity). Of punishment, "deservedly severe," from 1510s, which by Johnson's day (1755) was the only use.
condiment (n.): early 15c., from Old French condiment (13c.), from Latin condimentum "spice, seasoning, sauce," from condire "to preserve, pickle, season," variant of condere "to put away, store," from com- "together" (see com-) + -dere comb. form meaning "to put, place," from dare "to give" (see date (n.1)).
condition (n.): early 14c., condicioun, from Old French condicion "stipulation, state, behavior, social status" (12c., Modern French condition), from Latin condicionem (nominative condicio) "agreement, situation," from condicere "to speak with, talk together," from com- "together" (see com-) + dicere "to speak" (see diction). Evolution of meaning through "stipulation, condition," to "situation, mode of being."
condition (v.): late 15c., "to make conditions," from condition (n.). Meaning "to bring to a desired condition" is from 1844. Related: Conditioned; conditioning.
conditional (adj.): late 14c., condicionel, from Old French condicionel (Modern French conditionnel), from Latin conditionalis, from condicionem (see condition (n.)). Related: Conditionally.
conditioner (n.): c. 1600, "a bargainer," agent noun from condition (v.). Meaning "an agent that brings something into good condition" is from 1888; since c. 1960 usually in reference to hair care products. For about 20 years before that, it often was short for air conditioner.
condo (n.): 1964, short for condominium.
condole (v.): late 15c., "to sorrow," from Late Latin condolere "to suffer with another," from com- "with" (see com-) + dolere "to grieve" (see doleful). Meaning "to express condolences" is recorded from 1650s. Related: Condoled; condoling.