Online Etymology Dictionary

cathexis (n.): 1922, from Latinized form of Greek kathexis "holding, retention," from PIE root *segh- "to hold" (see scheme (n.)). Used by psychologists to render Freud's (libido)besetzung.
cathode (n.): 1834, from Latinized form of Greek kathodos "a way down," from kata- "down" (see cata-) + hodos "way" (see cede). Proposed by the Rev. William Whewell (1794-1866), English polymath, and published by English chemist and physicist Michael Faraday (1791-1867). So called from the path the electric current was supposed to take. Related: Cathodic; cathodal. Cathode ray first attested 1880, but the phenomenon known from 1859; cathode ray tube is from 1905.
catholic (adj.): mid-14c., "of the doctrines of the ancient Church," literally "universally accepted," from French catholique, from Church Latin catholicus "universal, general," from Greek katholikos, from phrase kath' holou "on the whole, in general," from kata "about" + genitive of holos "whole" (see safe (adj.)). Applied to the Church in Rome c. 1554, after the Reformation began. General sense of "of interest to all, universal" is from 1550s.
Catholic (n.): "member of the Roman Catholic church," 1560s, from Catholic (adj.).
Catholicism (n.): "faith and practice of the Catholic church," 1610s, from Catholic + -ism.
catholicity (n.): 1830, "catholicism," from catholic + -ity. Meaning "quality of being inclusive or comprehensive" is by 1843.
Catiline (adj.): from Lucius Sergius Catilina, Roman official who plotted an uprising 63 B.C.E. and was exposed by Cicero in a famous oration, taken since 1590s as a type of a reckless conspirator.
cation (n.): 1834, from Greek kation "going down," neuter present participle of katienai "to go down," from kata "down" (see cata-) + ienai "to go" (see ion). Proposed by the Rev. William Whewell (1794-1866), English polymath, and published by English physicist Michael Faraday.
catkin (n.): 1570s, from Dutch katteken "flowering stem of willow, birch, hazel, etc.," literally "kitten," diminutive of katte "cat" (see cat (n.)). So called for their soft, furry appearance.
catnap (n.): also cat-nap, cat's nap, by 1823, from cat (n.) + nap (n.). A nap such as a cat takes. As a verb from 1859.
catnip (n.): 1712, American English, from cat (n.) + nip, from Old English nepte "catnip," from Latin nepta, name of an aromatic herb. The older name is Middle English catmint (mid-13c.).
catoblepas (n.): late 14c., from Latin catoblepas, from Greek katobleps, from kato "downward" (related to kata-) + blepein "to look," but this might be ancient folk etymology. Name given by ancient authors to some African animal.
A wylde beest that hyghte Catoblefas and hath a lytyll body and nyce in all membres and a grete heed hangynge alway to-warde the erth. [John of Trevisa, translation of Bartholomew de Glanville's "De proprietatibus rerum," 1398]
catoptric (adj.): "pertaining to mirrors or a mirror," 1774, from Latinized form of Greek katoptrikos, from katoptron "mirror," from kata- "against" (see cata-) + stem of optos "seen, visible" (see optic) + instrumental suffix -tron. Related: Catoptrics; catoptrical.
catoptromancy (n.): "divination by means of a mirror," 1610s, from Latinized comb. form of Greek katoptron "mirror" (see catoptric) + -mancy.
catsuit (n.): also cat-suit, 1960, from cat (n.) + suit (n.).
catsup: see ketchup.
cattail (n.): also cat's tail, type of plant, mid-15c., from cat (n.) + tail (n.).
cattish (adj.): 1590s, "cat-like," from cat (n.) + -ish. From 1883 as "catty." Related: Cattishly; cattishness.
cattle (n.): mid-13c., "property," from Anglo-French catel "property" (Old North French catel, Old French chatel), from Medieval Latin capitale "property, stock," noun use of neuter of Latin adjective capitalis "principal, chief" (see capital (n.1)). Compare sense development of fee, pecuniary. Sense originally was of movable property, especially livestock; it began to be limited to "cows and bulls" from late 16c.
catty (adj.): 1886, "devious and spiteful," from cat (n.) + -y (2). Slightly earlier was cattish. Meaning "pertaining to cats" is from 1902. Related: Cattily; cattiness.
catty-cornered (adj., adv.): 1838, earlier cater-cornered (1835, American English), from now-obsolete cater "to set or move diagonally" (1570s), from Middle French catre "four," from Latin quattuor (see four). Compare carrefour.
catwalk (n.): 1885, "long, narrow footway," from cat (n.) + walk (n.); in reference to such narrowness of passage one has to cross carefully, as a cat walks. Originally of ships and theatrical back-stages. Application to fashion show runways is by 1942.
Caucasian (adj.): 1807, from Caucasus Mountains, between the Black and Caspian seas; applied to the "white" race 1795 (in German) by German anthropologist Johann Blumenbach, because its supposed ancestral homeland lay there; since abandoned as a historical/anthropological term. (See Aryan).
Caucasian (n.): "resident or native of the Caucasus," 1843; see Caucasus + -ian. Meaning "one of the 'white' race" is from 1958 (earlier Caucasoid, 1956).
Caucasus (n.): mountain range between Europe and the Middle East, from Latin Caucasus, from Greek kaukasis, said by Pliny ("Natural History," book six, chap. XVII) to be from a Scythian word similar to kroy-khasis, literally "(the mountain) ice-shining, white with snow." But possibly from a Pelasgian root *kau- meaning "mountain."
caucus (n.): "private meeting of party leaders," 1763, American English (New England), perhaps from an Algonquian word caucauasu "counselor, elder, adviser" in the dialect of Virginia, or from the Caucus Club of Boston, a 1760s social & political club whose name possibly derived from Modern Greek kaukos "drinking cup." Another old guess is caulker's (meeting) [Pickering, 1816], but OED finds this dismissable.
CAUCUS. This noun is used throughout the United States, as a cant term for those meetings, which are held by the different political parties, for the purpose of agreeing upon candidates for office, or concerting any measure, which they intend to carry at the subsequent public, or town meetings. [John Pickering, "A Vocabulary, or Collection of Words and Phrases Which Have Been Supposed to be Peculiar to the United States of America," Boston, 1816]

The word caucus, and its derivative caucusing, are often used in Boston. The last answers much to what we stile parliamenteering or electioneering. All my repeated applications to different gentlemen have not furnished me with a satisfactory account of the origin of caucus. It seems to mean, a number of persons, whether more or less, met together to consult upon adopting and prosecuting some scheme of policy, for carrying a favorite point. [William Gordon, "History, Rise, Progress, and Establishment of the Independence of the United States of America," London, 1788]
caucus (v.): 1850, from caucus (n.), but caucusing is attested from 1788.
caudal (adj.): 1660s, from Latin cauda "tail of an animal," which is of unknown origin, + -al (1).
caudillo (n.): dictator in Spain or Latin America, 1852, from Spanish caudillo, cabdillo "leader, chief," from Late Latin capitellum, diminutive of caput (genitive capitis) "head" (see capitulum). Later in Spain taken by Franco as a title in imitation of German Führer, Italian Duce.
caudle (n.): "hot drink," late 13c., from Old North French caudel (Old French chaudel, 12c., Modern French chaudeau), from Medieval Latin caldellum, diminutive of caldum, neuter of Latin caldus "warm" (see calorie).
caught: past tense and past participle of catch (v.), attested from 14c., predominant after c. 1800, replacing earlier catched. A rare instance of English strong verb with a French origin. This might have been by influence of Middle English lacchen (see latch (v.)), which also then meant "to catch" and was a synonym of catch (as their noun forms remain), and which then had past tense forms lahte, lauhte, laught. The influence happened before latch switched to its modern weak conjugation.
caul (n.): early 14c., "close-fitting cap worn by women," from French cale "cap," back-formation from calotte, from Italian callotta, from Latin calautica "type of female headdress with pendent lappets," a foreign word of unknown origin. Medical use, in reference to various membranes, dates to late 14c. Especially of the amnion enclosing the fetus before birth from 1540s. This, if the child is born draped in it, was supersititously supposed to protect against drowning (cauls were advertised for sale in British newspapers through World War I).
cauldron (n.): c. 1300, caudron, from Anglo-French caudrun, Old North French cauderon (Old French chauderon "cauldron, kettle"), from augmentative of Late Latin caldaria "cooking pot" (source of Spanish calderon, Italian calderone), from Latin calidarium "hot bath," from calidus "warm, hot" (see calorie). The -l- was inserted 15c. in imitation of Latin.
cauliflower (n.): 1590s, originally cole florye, from Italian cavoli fiori "flowered cabbage," plural of cavolo "cabbage" + fiore "flower" (from Latin flora; see flora).

First element is from Latin caulis "cabbage" (originally "stem, stalk") which was borrowed into Germanic and is the source of cole in cole-slaw and of Scottish kale. The front end of the word was re-Latinized from 18c.; the back end was influenced by flower (n.). The boxer's cauliflower ear is from 1907.
cauline (adj.): "pertaining to or growing on a stem," 1756, from Latin caulis "stalk" (see cole).
caulis (n.): "stem or stalk of a plant," Latin; see cole.
caulk (v.): late 14c., "to stop up crevices or cracks," from Old North French cauquer, from Late Latin calicare "to stop up chinks with lime," from Latin calx (2) "lime, limestone" (see chalk). Original sense is nautical, of making ships watertight. Related: Caulked; caulking. As a noun, "caulking material," by 1980 (caulking in this sense was used from 1743). Related: Caulker.
causal (adj.): 1530s, from Latin causalis "relating to a cause," from causa (see cause (n.)).
causality (n.): c. 1600, from causal + -ity.
causation (n.): 1640s, from Latin causationem (nominative causatio) "excuse, pretext," in Medieval Latin "action of causing," from causa (see cause).
causative (adj.): early 15c. (as a noun), from French causatif, from Latin causativus, from causa (see cause (n.)).
cause (n.): c. 1200, "reason for action, grounds for action; motive," from Old French cause "cause, reason; lawsuit, case in law" (12c.), and directly from Latin causa "a cause; a reason; interest; judicial process, lawsuit," which is of unknown origin. In English, sense of "matter of concern; side taken in controversy" is from c. 1300; that of "the source of an effect" is early 14c.; meaning "reason for something taking place" is late 14c. Cause célèbre "celebrated legal case" is 1763, from French. Cause why? "for what reason?" is in Chaucer.
cause (v.): late 14c., "produce an effect," also "impel, compel," from Old French causer "to cause" (13c.) and directly from Medieval Latin causare, from Latin causa "a cause; a reason; interest; judicial process, lawsuit," which is of unknown origin. Related: Caused; causing. Classical Latin causari meant "to plead, to debate a question."
causeway (n.): 1570s, from Middle English cauceweye "raised road" (mid-15c.), first element from Anglo-French cauce, Old North French cauciee (12c., Modern French chaussée), from Vulgar Latin *via calciata "paved way," from Latin calcis, genitive of calx (2) "limestone," or Late Latin calciare "to stamp with the heels, tread" (on notion of a road or mound across marshy ground made firm by treading down), from Latin calx (1) "heel." For second element, see way (n.).
caustic (adj.): c. 1400, "burning, corrosive," from Latin causticus "burning, caustic," from Greek kaustikos "capable of burning; corrosive," from kaustos "combustible; burnt," verbal adjective from kaiein, the Greek word for "to burn" (transitive and intransitive) in all periods, which is of uncertain origin with no certain cognates outside Greek. Figurative sense of "sarcastic" is attested from 1771. As a noun, early 15c., from the adjective.
cauterization (n.): c. 1400, from Old French cauterisation (14c.) and directly from Late Latin cauterizationem (nominative cauterizatio), noun of action from past participle stem of cauterizare (see cauterize).
cauterize (v.): c. 1400, from Old French cauterisier, from Late Latin cauterizare "to burn or brand with a hot iron," from Greek kauteriazein, from kauter "burning or branding iron," from kaiein "to burn" (see caustic). Related: Cauterized; cauterizing.
cautery (n.): 1540s, from Latin cauterium "branding iron," from Greek kauterion (see cauterize).
caution (n.): c. 1300, "bail, guarantee, pledge," from Old French caution "security, surety" (13c.), from Latin cautionem (nominative cautio) "caution, care, foresight, precaution," noun of action from past participle stem of cavere "to be on one's guard" (see caveat). The Latin sense re-emerged in English 16c.-17c. Meaning "word of warning" is from c. 1600.
caution (v.): "to warn," 1640s, from caution (n.). Related: Cautioned; cautioning.