Online Etymology Dictionary

cruller (n.): 1805, American English, apparently from Dutch kruller, from krullen "to curl," from Middle Dutch crullen, related to curl.
crumb (n.): Old English cruma "crumb, fragment," from a West Germanic root of obscure origin (cf. Middle Dutch crume, Dutch kruim, German krume). The -b- appeared mid-15c., in part by analogy with words like dumb, in part from crumble. Slang meaning "lousy person" is 1918, from crumb, U.S. slang for "body-louse" (1863), so called from resemblance.
crumble (v.): late 15c., kremelen, from Old English *crymelan, presumed frequentative of gecrymman "to break into crumbs," from cruma (see crumb). The -b- is 16c., probably on analogy of French-derived words like humble, where it belongs, or by influence of crumb. Related: Crumbled; crumbling.
crumby (adj.): 1731, "full of crumbs," from crumb + -y (2). Overlapping somewhat with crummy, but generally restricted to the more literal senses.
crummy (adj.): 1560s, "easily crumbled;" 1570s, "like bread," from crumb + -y (2). The second sense probably accounts for 18c. (and later in dialects) use, of a woman, "attractively plump, full-figured, buxom." Slang meaning "shoddy, filthy, inferior, poorly made" in use by 1859, probably is from the first sense, but influenced by crumb in its slang sense of "louse."
crumpet (n.): 1690s, perhaps from crompid cake "wafer," literally "curled-up cake" (1382; Wyclif's rendering of Hebrew raqiq in Ex. 29:23), from crompid, past participle of crumpen "curl up." Alternative etymology is from Celtic (cf. Breton krampoez "thin, flat cake"). Slang meaning "woman regarded as a sex object" is first recorded 1936.
crumple (v.): c.1300, crumplen, frequentative of crumpen "to curl up" (from Old English crump "bent, crooked"). Related: Crumpled; crumpling.
crunch (v.): 1814, from craunch (1630s), probably of imitative origin. Related: Crunched; crunching. The noun is 1836, from the verb; the sense of "critical moment" was popularized 1939 by Winston Churchill, who had used it in his 1938 biography of Marlborough.
crunchy (adj.): 1892, from crunch + -y (2). Student slang sense of "annoyingly intense about health or environmental issues" is by 1990, short for crunchy granola (considered as natural and wholesome); not entirely pejorative at first. Related: Crunchiness.
crunk (n.): by 1999, style of popular music developed in U.S. South in 1990s; often said to be a contraction of crazy drunk. It was used early in a sense of "cool, good."
crusade (n.): 1706, respelling of croisade (1570s), from Middle French croisade (16c.), Spanish cruzada, both from Medieval Latin cruciata, past participle of cruciare "to mark with a cross," from Latin crux (genitive crucis) "cross." Other Middle English forms were croiserie, creiserie. Figurative sense of "campaign against a public evil" is from 1786.
crusade (v.): 1732, from crusade (n.). Related: Crusaded; crusading.
crusader (n.): 1743, from crusade + -er (1). Earlier was croisader, from French croisadeur.
cruse (n.): "small vessel for liquids," early 15c., perhaps related to Old Norse krus "pot, tankard," from a general Germanic root of unknown origin. Cf. Middle Dutch cruese, Dutch kroes "cup, pot, mug," Middle Low German krus, Danish krus "mug, jug," German Krause "jug, mug."
crush (v.): mid-14c., from Old French cruissir (Modern French écraser), variant of croissir "to gnash (teeth), crash, break," perhaps from Frankish *krostjan "to gnash" (cf. Gothic kriustan, Old Swedish krysta "to gnash"). Figurative sense of "to humiliate, demoralize" is c.1600. Related: Crushed; crushing. Italian crosciare, Catalan cruxir, Spanish crujirare "to crack" are Germanic loan-words.
crush (n.): 1590s, "act of crushing," from crush (v.). Meaning "thick crowd" is from 1806. Sense of "person one is infatuated with" is first recorded 1884; to have a crush on is from 1913.
crust (v.): late 14c.; see crust (n.). Related: Crusted; crusting.
crust (n.): early 14c., "hard outer part of bread," from Old French crouste (13c., Modern French croûte) and directly from Latin crusta "rind, crust, shell, bark," from PIE *krus-to- "that which has been hardened," from root *kreus- "to begin to freeze, form a crust" (cf. Sanskrit krud- "make hard, thicken;" Avestan xruzdra- "hard;" Greek krystallos "ice, crystal," kryos "icy cold, frost;" Lettish kruwesis "frozen mud;" Old High German hrosa "ice, crust;" Old English hruse "earth;" Old Norse hroðr "scurf"). Meaning "outer shell of the earth" is from 1550s.
Crustacea (n.): 1814, Modern Latin neuter plural of crustaceus (animalia), literally "having a crust or shell," from Latin crusta "crust, rind, bark, hard shell" (see crust (n.)). Taken as a zoological classification by Lamarck, 1801; Cuvier (1798) had les insectes crustacées.
crustacean (n.): 1835, from Crustacea the class name. As an adjective, 1858 (earlier was crustaceous, 1640s).
crustation (n.): mid-17c., noun of action from crust (v.).
crusty (adj.): c.1400, from crust (n.) + -y (2). Figurative use, of persons, "short-tempered," is from 1560s.
crutch (n.): Old English crycce "crutch, staff," from Proto-Germanic *krukjo (cf. 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.): 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.): 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), 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)," cf. 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.): late 13c., from cry (v.).
crybaby (n.): 1851, American English, from cry + baby (n.).
cryo-: word-forming element meaning "very cold, freezing," from Latinized form of Greek kryo-, comb. form of kryos "icy cold," related to kryeros "chilling" (see crust (n.)).
cryogenic (adj.): 1902, from from cryogen "freezing mixture" (1875), from cryo- "freezing" + -genic "having to do with production" (see genus). Related: Cryogenics (1958).
crypt (n.): 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 *krau- "to conceal, hide" (cf. Old Church Slavonic kryjo, kryti "to hide"). Meaning "underground burial vault or chapel in a church" first attested 1789.
cryptic (adj.): 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-: 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.): 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.): 1650s, from French cryptographie or directly from Modern Latin cryptographia, from Greek kryptos "hidden" (see crypt) + -graphy. Related: Cryptograph; cryptographer.
cryptology (n.): 1640s, from crypto- + -ology.
cryselephantine (adj.): 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.): 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 *kru(s)- "hard, hard outer surface" (see 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.): 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.): chiefly British English spelling of crystallization; for spelling, see -ize.
crystallization (n.): 1660s, noun of action from crystallize + -ation. Figurative use is attested from 1842.
crystallize (v.): 1590s, from crystal + -ize. Figurative use is from 1660s. Related: Crystallized; crystallizing.
crystallized (adj.): c.1600, past participle adjective from crystallize. Of fruit, etc., from 1875.
cub (n.): 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: 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.): 1868, short for cubbyhole.
cubbyhole (n.): 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 (e.g. 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.): 1550s, from Middle French cube (13c.) and directly from Latin cubus, from Greek kybos "a cube, a six-sided die, vertebra," perhaps from PIE root *keu(b)- "to bend, turn." 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.): 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.): 1550s, from Middle French cubique (14c.), from Latin cubicus, from Greek kybikos, from kybos "cube" (see cube (n.)). Related: Cubical.
cubicle (n.): 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.