"theory or study of communication and control," coined 1948 by U.S. mathematician Norbert Wiener (1894-1964), with -ics + Latinized form of Greek kybernetes "steersman" (metaphorically "guide, governor"), from kybernan "to steer or pilot a ship, direct as a pilot," figuratively "to guide, govern," which is of uncertain origin. Beekes agrees that "the word has no cognates" and concludes "Foreign origin is probable." The construction is perhaps based on 1830s French cybernétique "the art of governing."ETD cybernetics (n.).2

cyberspace (n.)

"the online world of computer networks and especially the Internet, the environment in which communication over computer networks occurs," 1982, often written as two words at first, coined by science fiction writer William Gibson (best known for "Neuromancer") and used by him in a short story published in 1982, from cyber- + space (n.).ETD cyberspace (n.).2

cyborg (n.)

"a man-machine hybrid, a human modified by integrated machinery to have extended powers," 1960, a blend of the first elements of cybernetic and organism.ETD cyborg (n.).2

cycad (n.)

one of an order of gymnospermous plants, 1845, from Cycadaceae, the family name, Modern Latin, from Greek kykas, a word found in Theophrastus but now thought to be a scribal error for koikas "palm trees," accusative plural of koix, which probably is from an unknown non-Greek language. Related: Cycadaceous.ETD cycad (n.).2

cycle (n.)

late 14c., cicle, "perpetual circulating period of time, on the completion of which certain phenomena return in the same order," especially and originally in reference to astronomical phenomena, from Old French cicle and directly from Late Latin cyclus, from Greek kyklos "circle, wheel, any circular body," also "circular motion, cycle of events," from PIE kw(e)-kwl-o-, a suffixed, reduplicated form of the root *kwel- (1) "to revolve, move round."ETD cycle (n.).2

From 1660s as "any recurring round of operations or events" (as in life cycle). From 1821 as "single complete period in a cycle." Extended by 1842 to "any long period of years, an age." In literary use, "the aggregate of the legends or traditions around some real or mythical event or character" (1835).ETD cycle (n.).3

By 1884 as "recurring series of oscillations or operations in an engine, etc." From 1870 as short for motorcycle; by 1881 as short for bicycle or tricycle.ETD cycle (n.).4

cycle (v.)

1842, "revolve in cycles, occur or recur in cycles," from cycle (n.). Meaning "to ride a bicycle" is by 1881 (implied in cycling). Related: Cycled.ETD cycle (v.).2

cyclamen (n.)

one of a genus of bulbous plants native to southern Europe and western Asia, 1550s, from Medieval Latin cyclamen, from Latin cyclaminos, from Greek kyklaminos, also kyklamis, from kyklos "circle" (from PIE root *kwel- (1) "revolve, move round"). So called apparently in reference to the bulbous shape of the root.ETD cyclamen (n.).2

cyclic (adj.)

1794, "pertaining to or moving in a cycle or circle," from French cyclique (16c.), from Latin cyclicus, from Greek kyklikos "moving in a circle," from kyklos "circle, wheel, any circular body, circular motion, cycle of events" (see cycle (n.)). Sense of "connected to a literary cycle" is by 1822.ETD cyclic (adj.).2

cyclical (adj.)

1817, of a line, "returning into itself," from cyclic + -al (1). From 1834 as "pertaining to a cycle, cyclic." In botany, "rolled up circularly;" in zoology, "recurrent in successive circles."ETD cyclical (adj.).2

cyclist (n.)

"bicyclist," 1882; see bicycle + -ist. Cycler is from 1880. Saxonists preferred wheelman. Meaning "one who reckons by cycles or believes in the cyclic recurrence of certain classes of events" is from 1882.ETD cyclist (n.).2

cyclo-

before a vowel, cycl-, word-forming element in technical terms meaning "circle, ring, rotation," from Latinized form of Greek kyklos "circle, wheel, ring" (from PIE root *kwel- (1) "revolve, move round"). In organic chemistry it is used in forming chemical names of cyclic compounds.ETD cyclo-.2

cyclonic (adj.)

"pertaining to or of the nature of a cyclone," 1849, from cyclone + -ic. Cyclonal is from 1855.ETD cyclonic (adj.).2

cyclone (n.)

1848, "extensive storm characterized by the revolution of air around a calm center in which the wind blows spirally around the center," coined by British East India Company official Henry Piddington to describe the devastating storm of December 1789 in Coringa, India; irregularly formed from a Latinized form of Greek kyklon "moving in a circle, whirling around," present participle of kykloun "move in a circle, whirl," from kyklos "circle" (from PIE root *kwel- (1) "revolve, move round"). Applied to tornadoes from 1856.ETD cyclone (n.).2

Cyclops (n.)

(plural Cyclopes), in Greek mythology, a giant with one eye, circular and in the middle of the forehead, 1510s, from Latin Cyclops, from Greek kyklops, literally "round-eyed," from stem of kyklos "circle, circular body" (from PIE root *kwel- (1) "revolve, move round") + ops "eye" (from PIE root *okw- "to see").ETD Cyclops (n.).2

But in the Odyssey they were lawless gigantic cannibal shepherds in Sicily under their chief Polyphemus, and in other ancient tales they were race of giants from Thrace under a king Cyclops, who built the prehistoric walls and fortresses of Greece. Related: Cyclopic.ETD Cyclops (n.).3

Cyclopean (adj.)

"of or characteristic of the legendary Cyclopes of Greek mythology," 1640s, from Latin cyclopeus, from Greek kyklopeios, from kyklopes (see cyclops). Especially in reference to having a single eye in the middle of the forehead; also "vast, gigantic," and in reference to a style of ancient masonry, irregular or unhewn, fabled to be the work of a gigantic Thracian race (1822).ETD Cyclopean (adj.).2

cyclopedia (n.)

also cyclopaedia, 1728, a shortening of encyclopedia. Related: Encyclopedic, encyclopaedic.ETD cyclopedia (n.).2

cyclorama (n.)

"circular panorama, picture of a landscape, battle, etc., arranged on the interior surface of a cylindrical room or other space," 1840, from cyclo- + -rama "spectacle." Related: Cycloramic.ETD cyclorama (n.).2

cyclotron (n.)

"apparatus for accelerating charged atomic particles by causing them to revolve in orbits of increasing diameter," 1935, from cyclo- + ending from electron.ETD cyclotron (n.).2

cygnet (n.)

"a young swan," c. 1400, also signet before 17c., from Anglo-French cignet (mid-14c.), Anglo-Latin cygnettus, diminutives of Old French cigne, cisne "swan" (12c., Modern French cygne), from Latin cygnus, from Greek kyknos, which has been the subject of "abundant discussion" (Beekes) and is perhaps from PIE *(s)keuk- "to be white" (compare Sanskrit socati "to lighten, glow," sukra- "light, clear, white"). Spanish, Portuguese cisne, Italian cecero are from Medieval Latin cecinus, cicinus, a corruption of the classical Latin word.ETD cygnet (n.).2

cylinder (n.)

late 14c., chilindre, "portable sundial in the shape of a cylinder with a conical top," from Old French cylindre (14c.) and directly from Latin cylindrus "roller, cylinder," from Greek kylindros "a cylinder, roller, roll," from kylindein "to roll," which is of unknown origin.ETD cylinder (n.).2

From 1560s as "a solid figure which may be conceived as generated by the revolution of a rectangle about one of its sides." From 1690s as "chamber of a steam engine in which the force of the steam is exerted on the piston." By 1849 as "part of a revolver which contains the chamber for the cartridges." By 1878 as "cylindrical record for a phonograph."ETD cylinder (n.).3

cylindrical (adj.)

"having the form or properties of a cylinder," 1640s, probably from cylindric (but this is attested only from 1680s), from Latinized form of Greek kylindrikos, from kylindros (see cylinder) + -al (1).ETD cylindrical (adj.).2

cymbal (n.)

"one of a pair of plates of brass or bronze which, when struck together, produce a sharp, ringing sound," mid-15c., from Old English cimbal and from Old French cymbale (13c.), both from Latin cymbalum, from Greek kymbalon "a cymbal," from kymbē "bowl, drinking cup." This previously has been connected with Sanskrit kumbha-, Avestan xumba- "pot;" Middle Irish comm, cummal. Beekes writes that, for structural reasons, "the word cannot be inherited. It is rather a 'Wanderwort', which fits a vessel term very well."ETD cymbal (n.).2

Cymric (adj.)

"of or pertaining to the Welsh" and their kindred, the Cornish and Bretons, by 1833, 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 root *merg- "boundary, border." Compare Allobroges, name of a warlike people in Gallia Narbonensis, literally "those from another land." As from 1833 as a noun, "the language of the Cymry."ETD Cymric (adj.).2

cynanthropy (n.)

"form of madness in which the afflicted imagines himself to be a dog," 1590s, from Latinized form of Greek kynanthropos "of a dog-man," from kyōn (genitive kynos) "dog" (from PIE root *kwon- "dog") + anthrōpos "male human being, man" (see anthropo-).ETD cynanthropy (n.).2

cynic (n.)

1550s, "one of the ancient sect of philosophy founded by Antisthenes," from Latinized form of Greek kynikos "a follower of Antisthenes," literally "dog-like," from kyōn (genitive kynos) "dog" (from PIE root *kwon- "dog").ETD cynic (n.).2

Supposedly the name is a reference to the coarseness of life and sneering surliness of the philosophers, and the popular association even in ancient times was "dog-like" (Lucian has kyniskos "a little cynic," literally "puppy").ETD cynic (n.).3

But more likely it is from Kynosarge "The Gray Dog," the name of the gymnasium outside ancient Athens (for the use of those who were not pure Athenians) where Antisthenes (a pupil of Socrates), taught. Diogenes was the most famous. Meaning "sneering sarcastic person" is from 1590s. As an adjective from 1630s.ETD cynic (n.).4

cynical (adj.)

1580s, with a capital -c-, "resembling Cynic philosophers," from cynic + -al (1). By 1660s (with a lower-case -c-) the meaning had shaded into the general one of "disposed to disbelieve or doubt the sincerity or value of social usages or personal character or motives and to express it by sarcasm and sneers, disparaging of the motives of others, captious, peevish." Related: Cynically.ETD cynical (adj.).2

cynicism (n.)

1670s, "philosophy or doctrines of the Cynics" (indifference to pleasure, stoicism pushed to austerity, asceticism), from cynic + -ism. Meaning "cynical character" is from 1847. For nuances of usage, see humor (n.).ETD cynicism (n.).2

cynocephalic (adj.)

"having a head like a dog," 1825, from Latin, from Greek kyōn (genitive kynos) "dog" (from PIE root *kwon- "dog") + kephalikos "pertaining to the head," from kephalē "head" (see cephalo-). Middle English had cino-cephales "fabled race of dog-headed creatures" (c. 1300).ETD cynocephalic (adj.).2

cynosure (n.)

"something that strongly attracts attention," 1590s, from French cynosure (16c.), from Latin Cynosura, literally "dog's tail," an old name of the constellation (now Ursa Minor) containing what is now (but was not in ancient times) the North Star, the focus of navigation, at the tip of its tail; from Greek kynosoura, literally "dog's tail," from kyōn (genitive kynos; from PIE root *kwon- "dog") + oura "tail" (see arse). Apparently in ancient times the whole constellation was used as a rough indicator of the celestial north pole. Related: Cynosural.ETD cynosure (n.).2

Cynthia

fem. proper name, also a poetic name of the Moon, from Latin Cynthia dea "the Cynthian goddess," epithet of Artemis/Diana, who is said to have been born on Mt. Cynthus (Greek Kynthos) on the isle of Delos.ETD Cynthia.2

cypress (n.)

popular name of a type of evergreen tree noted for its dense, dark foliage and durable, fragrant wood, native to southern Europe and 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.ETD cypress (n.).2

Perhaps it is related to Hebrew gopher, name of the tree whose wood was used to make the ark (Genesis vi.14). Extended to similar trees of America, Australia, and Japan. An emblem of mourning for the dead, cypress branches were used at funeral.ETD cypress (n.).3

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 also meant "pertaining to Aphrodite," and "licentious, lewd," which is the earliest attested sense in English (1590s), and was applied 18c.-19c. to prostitutes.ETD Cyprian (adj.).2

Cypriot

1590s as an adjective, "of or pertaining to the island of Cyprus;" 1630s as an adjective, "native of inhabitant of Cyprus," from Latinized form of Greek Kypriotes, from Kypros "Cyprus" (see Cyprus).ETD Cypriot.2

Cyprus

large eastern Mediterranean island, late 14c., Cipre, Cipres, from Latinized form of Greek Kypros "land of cypress trees" (see cypress).ETD Cyprus.2

Cyrene

ancient Greek colony in Libya; the name is of unknown origin. Cyrenaic (1640s) typically refers to the philosophy ("practical hedonism") of Aristippus of Cyrene (c. 435-c. 356 B.C.E.); as a noun, "a Cyrenaic philosopher," from 1580s.ETD Cyrene.2

Cyrillic

1842, in reference to the alphabet adopted by Slavic people belonging to the Eastern Church, 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).ETD Cyrillic.2

Cyrus

masc. proper name, Latinized form of Greek Kyros, from Old Persian Kurush, a name of unknown etymology. In Hebrew the name is Koresh, and in that form it was taken c. 1990 by Wayne Howell of Texas, U.S., when he became head of the Branch Davidian church there.ETD Cyrus.2

cyst (n.)

"bladder-like bag or vesicle in an animal body," 1713, from Modern Latin cystis (in English as a Latin word from 1540s), from Greek kystis "bladder, pouch," which is of uncertain etymology.ETD cyst (n.).2

cystectomy (n.)

1883; see cyst + -ectomy "a cutting out."ETD cystectomy (n.).2

cystic (adj.)

1630s, "pertaining to the gall bladder," from French cystique (16c.), from Modern Latin cysticus, from Greek kystis "bladder, pouch," which is of unknown origin. Meaning "pertaining to a cyst" is from 1713. Cystic fibrosis coined in 1938.ETD cystic (adj.).2

cystitis (n.)

"inflammation of the bladder," 1774, from cyst + -itis "inflammation."ETD cystitis (n.).2

cystocele (n.)

"hernia or rupture formed by protrusion of the bladder," 1811, from French cystocèle, from Latinized form of Greek kystis "bladder" (which is of unknown origin) + kele "tumor, rupture, hernia" (see -cele).ETD cystocele (n.).2

cystoscopy (n.)

1910, "examination of the bladder with a cystoscope" (1889), from Latinized combining form of Greek kystis "bladder" (which is of unknown origin) + -scope. Related: Cystoscopic.ETD cystoscopy (n.).2

-cyte

word-forming element used in modern science to mean "of a cell," from Latinized form of Greek kytos "a hollow, receptacle, basket" (see cyto-).ETD -cyte.2

Cytherean (adj.)

also Cytherian, 1719, "pertaining to Venus," from Latin Cytherea "Venus," from Greek Kythereia, from Kythera, Ionian island where Aphrodite was fabled to have arisen from the sea.ETD Cytherean (adj.).2

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"); 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."ETD cyto-.2

cytology (n.)

"the study of the cells of organisms," 1857, from cyto- "cell" + -logy. Related: Cytologist (1884); cytological.ETD cytology (n.).2

cytoplasm (n.)

"protoplasm, organic substance forming the essential constituent of cells," 1870, from cyto- "cell" + -plasm. Related: Cytoplasmic.ETD cytoplasm (n.).2

cytosine (n.)

crystalline base which is one of the constituents of nucleic acids, 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]ETD cytosine (n.).2

cytotoxic (adj.)

"poisonous to cells," 1902, from cyto- + toxic. Related: Cytotoxin (1900); cytotoxicity.ETD cytotoxic (adj.).2

czar (n.)

the common title of the emperor of Russia, 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.ETD czar (n.).2

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.ETD czar (n.).3

Czech (n.)

"member of the westernmost branch of the Slavic people," the native name for Bohemians (and including the Moravians), 1848, from Czech český "Bohemian, Czech," which is said to be from the name of an ancestral chief (who is mentioned in English by 1837). Room says "some" derive it from a source akin to Czech četa "army." Meaning "the Czech language" and use as an adjective both are also from 1848. Sometimes in early use, Tshekh, from French.ETD Czech (n.).2

Czechoslovakia (n.)

Central European nation from 1919-1992, from Czecho-, Latinized combining form of Czech + Slovakia (see Slovak). Related: Czechoslovak; Czechoslovakian. Since the breakup the western part has been known in English as the Czech Republic or Czechia.ETD Czechoslovakia (n.).2

curly (adj.) — cybercafe (n.)

D — Dane (n.)