Online Etymology Dictionary

cycle (n.): late 14c., from Late Latin cyclus, from Greek kyklos "circle, wheel, any circular body, circular motion, cycle of events," from PIE kw(e)-kwl-o-, suffixed, reduplicated form of root *kwel- (1), also *kwele-, "to roll, to move round; wheel" (source also of Sanskrit cakram "circle, wheel," carati "he moves, wanders;" Avestan caraiti "applies himself," c'axra "chariot, wagon;" Greek polos "a round axis" (PIE *kw- becomes Greek p- before some vowels), polein "move around;" Latin colere "to frequent, dwell in, to cultivate, move around," cultus "tended, cultivated," hence also "polished," colonus "husbandman, tenant farmer, settler, colonist;" Lithuanian kelias "a road, a way;" Old Norse hvel, Old English hweol "wheel;" Old Church Slavonic kolo, Old Russian kolo, Polish koło, Russian koleso "a wheel").
cyclic (adj.): 1794, from French cyclique (16c.), from Latin cyclicus, from Greek kyklikos "moving in a circle," from kyklos (see cycle (n.)).
cyclical (adj.): 1817, from cyclic + -al (1).
cyclist (n.): "bicyclist," 1882; see bicycle + -ist. Saxonists preferred wheelman.
cyclo-: before a vowel, cycl-, word-forming element meaning "circle, ring, rotation," from Latinized form of Greek kyklo-, comb. form of kyklos "circle, wheel, ring" (see cycle (n.)).
cyclone (n.): 1848, coined by British East India Company official Henry Piddington to describe the devastating storm of December 1789 in Coringa, India; irregularly formed from Greek kyklon "moving in a circle, whirling around," present participle of kykloun "move in a circle, whirl," from kyklos "circle" (see cycle (n.)). Applied to tornados from 1856.
cyclonic (adj.): 1860, from cyclone + -ic.
cyclopean (adj.): 1640s, from Latin cyclopeus, from Greek kyklopeios, from kyklopes (see cyclops).
cyclops (n.): (plural cyclopes), 1510s, from Latin, from Greek kyklops, literally "round-eyed," from stem of kyklos (see cycle (n.)) + -ops (see eye (n.)). One of a race of one-eyed giants who forged thunderbolts for Zeus, built the walls of Mycenae, etc.
cyclorama (n.): "picture of a landscape on the interior surface of a cylindrical space," 1840, from cyclo- + -rama "spectacle."
cyclotron (n.): 1935, from cyclo- + ending from electron.
cygnet (n.): c. 1400, also signet before 17c., from Anglo-French, diminutive of Old French cigne, cisne "swan" (12c., Modern French cygne), from Latin cygnus, from Greek kyknos, perhaps from PIE *keuk- "to be white."
cylinder (n.): 1560s, from Middle French cylindre (14c.), from Latin cylindrus "roller, cylinder," from Greek kylindros "a cylinder, roller, roll," from kylindein "to roll," which is of unknown origin.
cylindrical (adj.): 1640s, probably from cylindric (but this is attested only from 1680s), from Greek kylindrikos, from kylindros (see cylinder) + -al (1).
cymbal (n.): from Old English cimbal and from Old French cymbale (13c.), both from Latin cymbalum, from Greek kymbalon "a cymbal," from kymbe "bowl, drinking cup."
Cymric (adj.): 1839, from Welsh Cymru "Wales," Cymry "the Welsh," plural of Cymro, probably from ancient combrox "compatriot," from British Celtic *kom-brogos, from collective prefix *kom- (see com-) + *brogos "district," from PIE *merg- "boundary, border" (see mark (n.1)). Compare Allobroges, name of a warlike people in Gallia Narbonensis, literally "those from another land."
cynic (n.): mid-16c., in reference to the ancient philosophy, from Greek kynikos "a follower of Antisthenes," literally "dog-like," from kyon (genitive kynos) "dog" (see canine). Supposedly from the sneering sarcasm of the philosophers, but more likely from Kynosarge "Gray Dog," name of the gymnasium outside ancient Athens (for the use of those who were not pure Athenians) where the founder, Antisthenes (a pupil of Socrates), taught. Diogenes was the most famous. Popular association even in ancient times was "dog-like" (Lucian has kyniskos "a little cynic," literally "puppy"). Meaning "sneering sarcastic person" is from 1590s.
cynical (adj.): 1580s, "resembling Cynic philosophers," from cynic + -al (1). By late 17c. the meaning had shaded into the general one of "critical, disparaging the motives of others, captious, sneering, peevish." Related: Cynically.
cynicism (n.): 1670s, "philosophy of the Cynics," from cynic + -ism. Meaning "cynical character" is from 1847. For nuances of usage of cynicism, see humor (n.).
cynosure (n.): 1590s, from Middle French cynosure (16c.), from Latin Cynosura, literally "dog's tail," the constellation (now Ursa Minor) containing the North Star, the focus of navigation, from Greek kynosoura, literally "dog's tail," from kyon (genitive kynos; see canine) + oura "tail" (see arse).
Cynthia: fem. proper name, also "the Moon," from Latin Cynthia dea "the Cynthian goddess," epithet of Artemis/Diana, said to have been born on Mt. Cynthus on Delos.
cypress (n.): type of evergreen tree (sacred to Pluto), late 12c., from Old French cipres (12c., Modern French cyprès), from Late Latin cypressus, from Latin cupressus, from Greek kyparissos, probably from an unknown pre-Greek Mediterranean language. Perhaps related to Hebrew gopher, name of the tree whose wood was used to make the ark (Gen. vi:14).
Cyprian (adj.): 1620s, "of Cyprus," from Latin Cyprianus, from Cyprius, from Greek Kyprios (see Cyprus). The island was famous in ancient times as the birthplace of Aphrodite and for erotic worship rituals offered to her there; hence Cyprian meant "licentious, lewd," the earliest attested sense in English (1590s) and was applied 18c.-19c. to prostitutes.
Cyprus: eatern Mediterranean island, from Greek Kypros "land of cypress trees" (see cypress).
Cyrene: ancient Greek colony in Libya; the name is of unknown origin. Cyrenaic referred to the philosophy ("practical hedonism") of Aristippus of Cyrene (c. 435-c. 356 B.C.E.).
Cyrillic: 1842, in reference to the Slavic alphabet, from St. Cyril, 9c. apostle of the Slavs, who supposedly invented it. The alphabet replaced earlier Glagolitic. The name Cyril is Late Latin Cyrillus, from Greek Kyrillos, literally "lordly, masterful," related to kyrios "lord, master" (see church).
Cyrus: Latinized form of Greek Kyros, from Old Persian Kurush, a name of unknown etymology. In Hebrew, Koresh, and in that form taken c. 1990 by Wayne Howell of Texas, U.S., when he became head of the Branch Davidian church there.
cyst (n.): 1713, from Modern Latin cystis (in English as a Latin word from 1540s), from Greek kystis "bladder, pouch."
cystic (adj.): 1630s, "pertaining to the gall bladder," from French cystique (16c.), from Modern Latin cysticus, from Greek kystis "bladder, pouch." Meaning "pertaining to a cyst" is from 1713. Cystic fibrosis coined in 1938.
cystitis (n.): c. 1780, from cyst + -itis "inflammation."
cystocele (n.): 1811, from French cystocèle, from Greek kystis "bladder, pouch" + kele "tumor."
cystoscopy (n.): 1910, from Greek kystis "bladder, pouch" + -oscopy (see -scope).
cyto-: before a vowel, cyt-, word-forming element, from Latinized form of Greek kytos "a hollow, receptacle, basket" (from PIE *ku-ti-, from root *(s)keu- "to cover, conceal;" see hide (n.1)); used in modern science since c. 1859 for "cell," perhaps especially from the sense (in Aristophanes) of "a cell of a hive of wasps or bees."
cytology (n.): 1857, from cyto- + -logy. Related: Cytologist (1884).
cytoplasm (n.): 1874, from cyto- + -plasm.
cytosine (n.): 1894, from German cytosin (1894), from cyto- "cell" + -ose + chemical suffix -ine (2). "The name cytosine (due to Kossel and Neumann) is misleading. Cytosine is not, like adenosine and guanosine, a nucleoside but the sugar-free base." [Flood]
cytotoxic (adj.): 1902, from cyto- + toxic. Related: Cytotoxicity.
czar (n.): 1550s, from Russian tsar, from Old Slavic tsesari, from Gothic kaisar, from Greek kaisar, from Latin Caesar. First adopted by Russian emperor Ivan IV, 1547.
The spelling with cz- is against the usage of all Slavonic languages; the word was so spelt by Herberstein, Rerum Moscovit. Commentarii, 1549, the chief early source of knowledge as to Russia in Western Europe, whence it passed into the Western Languages generally; in some of these it is now old-fashioned; the usual Ger. form is now zar; French adopted tsar during the 19th c. This also became frequent in English towards the end of that century, having been adopted by the Times newspaper as the most suitable English spelling. [OED]
The Germanic form of the word also is the source of Finnish keisari, Estonian keisar. The transferred sense of "person with dictatorial powers" is first recorded 1866, American English, initially in reference to President Andrew Johnson. The fem. czarina is 1717, from Italian czarina, from Ger. Zarin, fem. of Zar "czar." The Russian fem. form is tsaritsa. His son is tsarevitch, his daughter is tsarevna.
Czech: said to be from the name of an ancestral chief, but perhaps from a source akin to Czech četa "army."
Czechoslovakia (n.): Central European nation from 1919-1992, from Czecho-, Latinized comb. form of Czech + Slovakia (see Slovak).