crustation (n.) Look up crustation at Dictionary.com
mid-17c., noun of action from crust (v.).
crusty (adj.) Look up crusty at Dictionary.com
c. 1400, from crust (n.) + -y (2). Figurative use, of persons, "short-tempered," is from 1560s.
crutch (n.) Look up crutch at Dictionary.com
Old English crycce "crutch, staff," from Proto-Germanic *krukjo (source also of Old Saxon krukka, Middle Dutch crucke, Old High German krucka, German Kröcke "crutch," related to Old Norse krokr "hook;" see crook). Figurative sense is first recorded c. 1600. As a verb, from 1640s. Italian gruccia "crutch," crocco "hook" are Germanic loan-words.
crux (n.) Look up crux at Dictionary.com
1814, "cross," from Latin crux "cross" (see cross (n.)). Figurative use for "a central difficulty," is older, from 1718; perhaps from Latin crux interpretum "a point in a text that is impossible to interpret," in which the literal sense is something like "crossroads of interpreters." Extended sense of "central point" is from 1888.
cry (v.) Look up cry at Dictionary.com
early 13c., "beg, implore," from Old French crier, from Vulgar Latin *critare, from Latin quiritare "to wail, shriek" (source of Italian gridare, Old Spanish cridar, Spanish and Portuguese gritar), which is of uncertain origin; perhaps a variant of quirritare "to squeal like a pig," from *quis, echoic of squealing, despite ancient folk etymology that traces it to "call for the help of the Quirites," the Roman constabulary. The meaning was extended 13c. to weep, which it largely replaced by 16c. Related: Cried; crying.

Most languages, in common with English, use the general word for "cry out, shout, wail" to also mean "weep, shed tears to express pain or grief." Romance and Slavic, however, use words for this whose ultimate meaning is "beat (the breast)," compare French pleurer, Spanish llorar, both from Latin plorare "cry aloud," but probably originally plodere "beat, clap the hands." Also Italian piangere (cognate with French plaindre "lament, pity") from Latin plangere, originally "beat," but especially of the breast, as a sign of grief. U.S. colloquial for crying out loud is 1924, probably another euphemism for for Christ's sake.
cry (n.) Look up cry at Dictionary.com
late 13c., from cry (v.).
crybaby (n.) Look up crybaby at Dictionary.com
1851, American English, from cry + baby (n.).
cryo- Look up cryo- at Dictionary.com
word-forming element meaning "very cold, freezing," from Latinized form of Greek kryo-, comb. form of kryos "icy cold," related to kryeros "chilling" (from PIE root *kreus- "to begin to freeze, form a crust").
cryogenic (adj.) Look up cryogenic at Dictionary.com
1902, from cryogen "freezing mixture" (1875), from cryo- "freezing" + -genic "having to do with production" (from PIE root *gene- "give birth, beget"). Related: Cryogenics (1958).
crypt (n.) Look up crypt at Dictionary.com
early 15c., "grotto, cavern," from Latin crypta "vault, cavern," from Greek krypte (short for krypte kamara "hidden vault"), fem. of kryptos "hidden," verbal adjective from kryptein "to hide," from PIE root *krau- "to conceal, hide" (source also of Old Church Slavonic kryjo, kryti "to hide"). Meaning "underground burial vault or chapel in a church" first attested 1789.
cryptic (adj.) Look up cryptic at Dictionary.com
1630s, "hidden, occult, mystical," from Late Latin crypticus, from Greek kryptikos "fit for concealing," from kryptos "hidden" (see crypt). Meaning "mysterious, enigmatic" is recorded from 1920. Related: Cryptically.
crypto- Look up crypto- at Dictionary.com
before vowels crypt-, word-forming element meaning "secret" or "hidden," used in forming English words since at least 1760, from Latinized form of Greek kryptos "hidden, concealed, secret" (see crypt; the Greek comb. form was krypho-). Crypto-fascist is attested from 1937; crypto-communist from 1946.
cryptogram (n.) Look up cryptogram at Dictionary.com
1880, from crypto- + gram "word, letter." A modern word coined in English; though the elements are Greek, the ancient Greeks would find it barbarous.
cryptography (n.) Look up cryptography at Dictionary.com
1650s, from French cryptographie or directly from Modern Latin cryptographia, from Greek kryptos "hidden" (see crypt) + -graphy. Related: Cryptograph; cryptographer.
cryptology (n.) Look up cryptology at Dictionary.com
1640s, from crypto- + -ology.
cryselephantine (adj.) Look up cryselephantine at Dictionary.com
1827, from Greek khryselephantinos "of gold and ivory," applied to statues overlaid with gold and ivory, such as Athene Parthenos and Olympian Zeus.
crystal (n.) Look up crystal at Dictionary.com
Old English cristal "clear ice, clear mineral," from Old French cristal (12c., Modern French crystal), from Latin crystallus "crystal, ice," from Greek krystallos, from kryos "frost," from PIE root *kreus- "to begin to freeze, form a crust." Spelling adopted the Latin form 15c.-17c. The mineral has been so-called since Old English; it was regarded by the ancients as a sort of fossilized ice. As a shortened form of crystal-glass it dates from 1590s. As an adjective, from late 14c.
crystalline (adj.) Look up crystalline at Dictionary.com
late 14c., from Old French cristalin "like crystal" (Modern French crystallin), from Latin crystallinus, from Greek krystallinos "of crystal," from krystallos (see crystal).
crystallisation (n.) Look up crystallisation at Dictionary.com
chiefly British English spelling of crystallization; for spelling, see -ize.
crystallization (n.) Look up crystallization at Dictionary.com
1660s, noun of action from crystallize + -ation. Figurative use is attested from 1842.
crystallize (v.) Look up crystallize at Dictionary.com
1590s, from crystal + -ize. Figurative use is from 1660s. Related: Crystallized; crystallizing.
crystallized (adj.) Look up crystallized at Dictionary.com
c. 1600, past participle adjective from crystallize. Of fruit, etc., from 1875.
cub (n.) Look up cub at Dictionary.com
1520s, cubbe "young fox," of unknown origin; perhaps from Old Irish cuib "whelp," or from Old Norse kobbi "seal." Extended to the young of bears, lions, etc., after 1590s. The native word was whelp. Cub Scout is from 1922.
Cuba Look up Cuba at Dictionary.com
said to be from Taino (Arawakan) Cubanacan, the name of the people who occupied the island. Related: Cuban (1829), Cuban heel (1908); Cuban Missile Crisis (October 16-28, 1962).
cubby (n.) Look up cubby at Dictionary.com
1868, short for cubbyhole.
cubbyhole (n.) Look up cubbyhole at Dictionary.com
1825, the first element possibly from a diminutive of cub "stall, pen, cattle shed, coop, hutch" (1540s), a dialect word with apparent cognates in Low German (such as East Frisian kubbing, Dutch kub). Or related to cuddy "small room, cupboard" (1793), originally "small cabin in a boat" (1650s), from Dutch kajuit, from French cahute. Or perhaps simply a children's made-up word.
cube (n.) Look up cube at Dictionary.com
1550s, from Middle French cube (13c.) and directly from Latin cubus, from Greek kybos "a six-sided die," used metaphorically of dice-like blocks of any sort, also "cake; piece of salted fish; vertebra," of uncertain origin. Beekes points out that "words for dice are often loans" and that "the Lydians claimed to have invented the game" of kybos. The mathematical sense is from 1550s in English (it also was in the ancient Greek word: the Greeks threw with three dice; the highest possible roll was three sixes).
cube (v.) Look up cube at Dictionary.com
1580s in the mathematical sense; 1947 with meaning "cut in cubes," from cube (n.). The Greek verbal derivatives from the noun all referred to dice-throwing and gambling. Related: Cubed; cubing.
cubic (adj.) Look up cubic at Dictionary.com
1550s, from Middle French cubique (14c.), from Latin cubicus, from Greek kybikos, from kybos "cube" (see cube (n.)). Related: Cubical.
cubicle (n.) Look up cubicle at Dictionary.com
mid-15c., "bedroom," from Latin cubiculum "bedroom," from cubare "to lie down," originally "bend oneself," from PIE root *keu(b)- "to bend, turn." With Latin -clom, suffix denoting place. Obsolete from 16c. but revived 19c. for "dormitory sleeping compartment," sense of "any partitioned space" (such as a library carrel or, later, office work station) is first recorded 1926.
cubism (n.) Look up cubism at Dictionary.com
1911, from French cubisme, from cube (see cube (n.)), said to have been coined by French art critic Louis Vauxcelles at the 1908 Salon des Indépendants in reference to a work by Georges Braque. Related: Cubist.
cubit (n.) Look up cubit at Dictionary.com
ancient unit of measure based on the forearm from elbow to fingertip, usually from 18 to 22 inches, early 14c., from Latin cubitum "the elbow," from PIE *keu(b)- "to bend." Such a measure, known by a word meaning "forearm" or the like, was known to many peoples (Greek pekhys, Hebrew ammah, English ell).
cuboid (adj.) Look up cuboid at Dictionary.com
"cube-like," 1829, a modern coinage; see cube (n.) + -oid.
cucking stool (n.) Look up cucking stool at Dictionary.com
early 13c., from cuck "to void excrement," from Old Norse kuka "feces" (the chair was sometimes in the form of a close-stool), from PIE root *kakka- "to defecate." Also known as trebucket and castigatory, it was used on disorderly women and fraudulent tradesmen, either in the form of public exposure to ridicule or for ducking in a pond.
cuckold (n.) Look up cuckold at Dictionary.com
mid-13c., kukewald, from Old French cucuault, from cocu (see cuckoo) + pejorative suffix -ault, of Germanic origin. So called from the female bird's alleged habit of changing mates, or her authentic habit of leaving eggs in another bird's nest.

In Modern French the identity is more obvious: Coucou for the bird and cocu for the betrayed husband. German Hahnrei (13c.), from Low German, is of obscure origin. The second element seems to be connected to words for "ardent," and suggests perhaps "sexually aggressive hen," with transferal to humans, but Kluge suggests rather a connection to words for "capon" and "castrated." Related: Cuckoldry.
cuckold (v.) Look up cuckold at Dictionary.com
1580s, from cuckold (n.). Related: Cuckolded; cuckolding.
cuckoo (n.) Look up cuckoo at Dictionary.com
mid-13c., from Old French cocu "cuckoo," also "cuckold," echoic of the male bird's mating cry (compare Greek kokkyx, Latin cuculus, Middle Irish cuach, Sanskrit kokilas). Slang adjectival sense of "crazy" is American English, 1918, but noun meaning "stupid person" is recorded by 1580s, perhaps from the bird's unvarying, oft-repeated call. The Old English name was geac, cognate with Old Norse gaukr, source of Scottish and northern English gowk. The Germanic words presumably originally were echoic, too, but had drifted in form. Cuckoo clock is from 1789.
cucumber (n.) Look up cucumber at Dictionary.com
late 14c., from Old French cocombre (13c., Modern French concombre), from Latin cucumerem (nominative cucumis), perhaps from a pre-Italic Mediterranean language. The Latin word also is the source of Italian cocomero, Spanish cohombro, Portuguese cogombro. Replaced Old English eorþæppla (plural), literally "earth-apples."

Cowcumber was common form 17c.-18c., and that pronunciation lingered into 19c. Planted as a garden vegetable by 1609 by Jamestown colonists. Phrase cool as a cucumber (c. 1732) embodies ancient folk knowledge confirmed by science in 1970: inside of a field cucumber on a warm day is 20 degrees cooler than the air temperature.
cud (n.) Look up cud at Dictionary.com
Old English cudu "cud," earlier cwudu, common Germanic (compare Old Norse kvaða "resin," Old High German quiti "glue," German Kitt "putty").
cuddle (v.) Look up cuddle at Dictionary.com
early 16c. (implied in cudlyng), perhaps a variant or frequentative form of obsolete cull, coll "to embrace" (see collar (n.)); or perhaps from Middle English *couthelen, from couth "known," hence "comfortable with." It has a spotty early history and seems to have been a nursery word at first. Related: Cuddled; cuddling.
cuddly (adj.) Look up cuddly at Dictionary.com
1863, from cuddle + -y (2).
cudgel (v.) Look up cudgel at Dictionary.com
"to beat with a cudgel," 1590s, from cudgel (n.). Related: Cudgeled; cudgeling.
cudgel (n.) Look up cudgel at Dictionary.com
Old English cycgel "club with rounded head;" perhaps from PIE *geu- "to curve, bend."
cue (n.2) Look up cue at Dictionary.com
"billiard stick," 1749, variant of queue (n.). Cue ball first recorded 1881.
cue (v.) Look up cue at Dictionary.com
1928, from cue (n.1). Related: Cued, cueing.
cue (n.1) Look up cue at Dictionary.com
"stage direction," 1550s, from Q, which was used 16c., 17c. in stage plays to indicate actors' entrances, probably as an abbreviation of Latin quando "when" (from PIE root *kwo-, stem of relative and interrogative pronouns) or a similar Latin adverb. Shakespeare's printed texts have it as both Q and cue.
cuff (n.) Look up cuff at Dictionary.com
"bottom of a sleeve," mid-14c., cuffe "hand covering, mitten, glove," perhaps somehow from Medieval Latin cuffia "head covering," which is of uncertain origin. Sense of "band around the sleeve" is first attested 1520s; sense of "hem of trousers" is 1911. Off the cuff "extemporaneously" is 1938 American English colloquial, suggesting an actor or speaker reading from notes jotted on his shirt sleeves rather than learned lines. Cuff links is from 1897.
cuff (v.2) Look up cuff at Dictionary.com
"hit," 1520s, of unknown origin, perhaps from Swedish kuffa "to thrust, push." Related: Cuffed; cuffing. As a noun from 1560s.
cuff (v.1) Look up cuff at Dictionary.com
"to put a cuff on," 1690s, from cuff (n.). Related: Cuffed; cuffing.
cui bono Look up cui bono at Dictionary.com
a Latin phrase from Cicero. It means "to whom for a benefit," or "who profits by it?" not "to what good purpose?" as is often erroneously claimed. From cui "to? for whom?," an old form preserved here in the dative form of the interrogative pronoun quis "who?" (from PIE root *kwo-, stem of relative and interrogative pronouns) + bono "good" (see bene-).