caliper (n.) Look up caliper at Dictionary.com
"instrument for measuring diameters," 1620s, short for calliper compass (1580s), a device used to measure calibers, from a corrupt form of caliber (q.v.). Usually in the plural, calipers.
caliph (n.) Look up caliph at Dictionary.com
title given to the successor of Muhammad as leader of the community and defender of the faith, late 14c., from Old French caliphe (12c., also algalife), from Medieval Latin califa, from Arabic khalifa "successor" (from khalafa "succeed"); originally Abu-Bakr, who succeeded Muhammad in the role of leader of the faithful after the prophet's death.
caliphate (n.) Look up caliphate at Dictionary.com
"dominion of a caliph," 1610s, from caliph + -ate (1). Meaning "rank of a caliph" is recorded from 1753.
calisthenics (n.) Look up calisthenics at Dictionary.com
also callisthenics, kind of light gymnastics, 1847, (the adjective calisthenic/callisthenic is from 1839), formed on model of French callisthenie, from Latinized combining form of Greek kallos "beauty" (see Callisto) + sthenos "strength, power, ability, might" (perhaps from PIE root *segh- "to have, hold," on the notion of "steadfastness, toughness") + -ics. The proper Greek, if there was such a word in Greek, would have been *kallistheneia. Originally, gymnastic exercises suitable for girls and meant to develop the figure and promote graceful movement. A place for doing it was a callisthenium.
call (n.) Look up call at Dictionary.com
early 14c., "a loud cry, an outcry," also "a summons, an invitation," from call (v.). In later use, "a summons" (by bugle, drum, etc.) to military men to perform some duty, also "the cry or note of a bird." Sense of "a short formal visit" is from 1862. Colloquially, "occasion, cause."
call (v.) Look up call at Dictionary.com
Old English ceallian "to shout, utter in a loud voice" (a less common verb in this sense than clipian); replaced by related Old Norse kalla "to cry loudly," from Proto-Germanic *kall- (source also of Middle Dutch kallen "to speak, say, tell," Dutch kallen "to talk, chatter," Old High German kallon "to speak loudly, call"), from PIE root *gal- "to call, shout." Related: Called; calling.

Meanings "ask for, pray for; demand, order" and "give a name to, apply by way of designation" are mid-13c. From c. 1300 as "to summon, invite or command to come." Coin-toss sense is from 1801; poker sense "demand that the hands be shown" is by 1889. Meaning "to make a short stop or visit" (Middle English) was literally "to stand at the door and call." Telephone/telegraph sense is from 1889.

To call (something) off "cancel" is modern; in 19c. call off meant "summon away, divert." To call for "demand, require" is modern. To call out someone to fight (1823) corresponds to French provoquer. To call it a day is from 1834.
call girl (n.) Look up call girl at Dictionary.com
"prostitute who makes appointments by phone," c. 1900, from call + girl.
calla (n.) Look up calla at Dictionary.com
marsh-plant found in colder parts of Europe and America, from Latin calla, the name in Pliny of an unidentified plant, perhaps a mistake for calyx. The common calla-lily is a related species, not a lily but so called for the appearance of the flowers.
caller (n.) Look up caller at Dictionary.com
c. 1500, "one who proclaims," agent noun from call (v.). Meaning "one who announces step changes at a dance" is recorded from 1882; "one who places a telephone call," 1898. Meaning "a social visitor" is attested from 1786.
calligraphy (n.) Look up calligraphy at Dictionary.com
"the art of beautiful writing, elegant penmanship," 1610s, from Greek kaligraphia, from kallos "beauty" (see Callisto) + graphein "to write" (see -graphy). Related: Calligrapher; calligraphic. The usual combining form in Greek was kalli- "beautiful, fine, happy, favorable;" kalo- was a later, rarer alternative form.
calling (n.) Look up calling at Dictionary.com
mid-13c., "outcry, shouting," also "a summons or invitation," verbal noun from call (v.). The sense "vocation, profession, trade, occupation" traces to I Corinthians vii.20.
calliope (n.) Look up calliope at Dictionary.com
"harsh-sounding steam-whistle keyboard organ," 1858, named for Calliope, ninth and chief muse, presiding over eloquence and epic poetry, Latinized from Greek Kalliope, literally "beautiful-voiced," from kalli-, combining form of kallos "beauty" (see Callisto) + opos (genitive of *ops) "voice," from PIE root *wekw- "to speak."
calliper (n.) Look up calliper at Dictionary.com
variant of caliper. Related: Callipers.
callipygian (adj.) Look up callipygian at Dictionary.com
"of, pertaining to, or having beautiful buttocks," 1800, Latinized from Greek kallipygos, name of a statue of Aphrodite at Syracuse, from kalli-, combining form of kallos "beauty" (see Callisto) + pyge "rump, buttocks." Sir Thomas Browne (1646) refers to "Callipygæ and women largely composed behinde."
Callisto Look up Callisto at Dictionary.com
fourth moon of Jupiter; in classical mythology a nymph, mother of Arcas by Zeus, turned to a bear by Hera, from Greek kallistos, superlative of kalos "beautiful, beauteous, noble, good," and its derived noun kallos "beauty," which is of uncertain origin, from PIE *kal-wo-, perhaps related to Sanskrit kalyana "beautiful." Feminized as proper name Callista.
callithumpian (adj.) Look up callithumpian at Dictionary.com
"pertaining to a noisy concert or serenade," also the name of the concert itself, 1836, U.S. colloquial, probably a fanciful construction. The "English Dialect Dictionary" reports Gallithumpians as a Dorset and Devon word from 1790s for a society of radical social reformers, and also in reference to "noisy disturbers of elections and meetings" (1770s). The U.S. reference is most commonly "a band of discordant instruments" or banging on tin pots and pans, blowing horns, etc., especially to "serenade" a newlywed couple to show disapproval of one or the other or the match.
callosal (adj.) Look up callosal at Dictionary.com
"pertaining to the corpus callosum," from Latin callosus (see callous) + -al (1).
callous (adj.) Look up callous at Dictionary.com
c. 1400, "hardened," in the physical sense, from Latin callosus "thick-skinned," from callus, callum "hard skin" (see callus). The figurative sense of "unfeeling, hardened in the mind" appeared in English by 1670s. Related: Callously; callousness.
callow (adj.) Look up callow at Dictionary.com
Old English calu "bare, bald," from Proto-Germanic *kalwa- (source also of Middle Dutch calu, Dutch kaal, Old High German kalo, German Kahl), from PIE root *gal- (1) "bald, naked" (source also of Russian golyi "smooth, bald"). From young birds with no feathers, meaning extended to any young inexperienced thing or creature (1570s), hence "youthful, juvenile, immature." Apparently not related to Latin calvus "bald."
callus (n.) Look up callus at Dictionary.com
"hardened skin," 1560s, from Latin callus, variant of callum "hard skin," related to callere "be hard," from Proto-Italic *kaln/so- "hard;" PIE source uncertain. Likely cognates are Old Irish calath, calad, Welsh caled "hard;" Old Church Slavonic kaliti "to cool, harden," Russian kalit "to heat, roast," Serbo-Croatian kaliti "to temper, case-harden."
calm (adj.) Look up calm at Dictionary.com
late 14c., of the sea, "windless, without motion or agitation;" of a wind, "light, gentle," from Old French calme "tranquility, quiet," traditionally from Old Italian calma, from Late Latin cauma "heat of the mid-day sun" (in Italy, a time when everything rests and is still), from Greek kauma "heat" (especially of the sun), from kaiein "to burn" (see caustic). Spelling influenced by Latin calere "to be hot." Figurative application to social or mental conditions, "freedom from agitation or passion," is 16c.
calm (n.) Look up calm at Dictionary.com
c. 1400, "absence of storm or wind," from Old French calme, carme "stillness, quiet, tranquility," from the adjective (see calm (adj.)). Figurative sense "peaceful manner, mild bearing" is from early 15c.
calm (v.) Look up calm at Dictionary.com
late 14c., "to become calm," from Old French calmer or from calm (adj.). Also transitive, "to make still or quiet." Related: Calmed; calming.
calmative (adj.) Look up calmative at Dictionary.com
"quieting excessive action," by 1831, from French calmatif; see calm (adj.) + -ative. A hybrid word; purists prefer sedative. "The Latinic suffix is here defensible on the ground of It. and Sp. calmar, F. calmer ...." [OED]. Also as a noun, "a quieting drug."
calmly (adv.) Look up calmly at Dictionary.com
"quietly, peacefully," 1590s, from calm (adj.) + -ly (2).
calmness (n.) Look up calmness at Dictionary.com
"quietness, stillness, tranquility," 1510s, from calm (adj.) + -ness.
calomel (n.) Look up calomel at Dictionary.com
old name for mercurous chloride, 1670s, from French calomel, supposedly (Littré) from Greek kalos "beautiful" (see Callisto) + melas "black;" but as the powder is yellowish-white this seems difficult. "It is perhaps of significance that the salt is blackened by ammonia and alkalis" [Flood].
Calor (n.) Look up Calor at Dictionary.com
proprietary name for a type of liquid gas sold in Britain, 1936, from Latin calor, literally "heat" (from PIE root *kele- (1) "warm").
caloric (n.) Look up caloric at Dictionary.com
hypothetical fluid in a now-discarded model of heat exchange, 1792, from French calorique, coined in this sense by Lavoisier, from Latin calorem "heat" (nominative calor), from PIE root *kele- (1) "warm." The adjective, "pertaining to heat or the principle of heat," is recorded from 1865.
calorie (n.) Look up calorie at Dictionary.com
unit of heat in physics, 1866, from French calorie, from Latin calor (genitive caloris) "heat," from PIE *kle-os-, suffixed form of root *kele- (1) "warm." In scientific use, largely replaced 1950 by the joule. As a unit of energy, defined as "heat required to raise 1 gram of water 1 degree Celsius" (the small or gram calorie), but also as "heat required to raise 1 kilogram of water 1 degree Celsius" (the large calorie or kilocalorie).
calorimeter (n.) Look up calorimeter at Dictionary.com
"apparatus for measuring heat given off by a body," 1794, from Latin calor "heat" (from PIE root *kele- (1) "warm") + -meter. A hybrid word. Related: Calorimetric; calorimetry.
calque (n.) Look up calque at Dictionary.com
"loan translation of a foreign word or phrase," from French calque, literally "a copy," from calquer "to trace by rubbing" (itself borrowed in English 1660s as calk "to copy by tracing"), introduced 16c. from Italian calcare, from Latin calcare "to tread, to press down."
calumet (n.) Look up calumet at Dictionary.com
kind of tobacco pipe used by North American Indians, 1660s, from Canadian French calumet, from Norman French calumet "pipe, reed pipe" (Old French chalemel, 12c., Modern French chalumeau), from Latin calamellus, diminutive of calamus "reed; something made of reed or shaped like a reed" (see shawm).
calumniate (v.) Look up calumniate at Dictionary.com
"to knowingly utter false charges," 1550s, from Latin calumniatus, past participle of calumniari "to accuse falsely," from calumnia "slander, false accusation" (see calumny). A doublet of challenge. Related: Calumniated; calumniating.
calumniation (n.) Look up calumniation at Dictionary.com
1540s, noun of action from calumniate (v.).
calumniator (n.) Look up calumniator at Dictionary.com
"one who falsely and knowingly accuses another of anything disgraceful or maliciously propagates false reports," 1690s, from Latin calumniator, agent noun from calumniari (see calumniate (v.)). Related: Calumniatory.
calumnious (adj.) Look up calumnious at Dictionary.com
"slanderous, using calumny," late 15c., from Latin calumniosus, from calumnia (see calumny). Related: Calumniously; calumniousness.
calumny (n.) Look up calumny at Dictionary.com
"False & malicious misrepresentation of the words or actions of others, calculated to injure their reputation" [Fowler], mid-15c., from Middle French calomnie (15c.), from Latin calumnia "trickery, subterfuge, misrepresentation, malicious charge," from calvi "to trick, deceive."

PIE cognates include Greek kelein "to bewitch, cast a spell," Gothic holon "to slander," Old Norse hol "praise, flattery," Old English hol "slander," holian "to to betray," Old High German huolen "to deceive." The whole group is perhaps from the same root as call (v.). A doublet of challenge.
Calvary Look up Calvary at Dictionary.com
name of the mount of the Crucifixion, late 14c., from Latin Calvaria (Greek Kraniou topos), translating Aramaic gulgulta "place of the skull" (see Golgotha). Rendered literally in Old English as Heafodpannan stow. Latin Calvaria is related to calvus "bald" (see Calvin).
calve (v.) Look up calve at Dictionary.com
"to bring forth a calf or calves," Old English cealfian, from cealf "calf" (see calf (n.1)). Of glaciers, "to lose a portion by an iceberg breaking off," 1837. Related: Calved; calving.
Calvin Look up Calvin at Dictionary.com
John Calvin (1509-1564), French Protestant leader and theologian, born Jean Caulvin, the surname related to French Chauvin (compare chauvinism), from Latin Calvinus, a Roman cognomen, literally "bald," from calvus "bald," from PIE *kle-wo- "bald."
Calvinism (n.) Look up Calvinism at Dictionary.com
1560s, from John Calvin (1509-1564), French Protestant reformer and theologian, + -ism. Alternative form Calvinian was in use in 1566. Generalized association with stern moral codes and predestination is attested at least since 1853. Related: Calvinist; Calvinistic.
Calypso Look up Calypso at Dictionary.com
sea nymph in the "Odyssey," literally "hidden, hider" (perhaps originally a death goddess) from Greek kalyptein "to cover, conceal," from PIE root *kel- (1) "to cover, conceal, save," which also is the source of English Hell. The type of West Indian song is so called from 1934, but the origin of the name is obscure.
calypto- Look up calypto- at Dictionary.com
word-forming element meaning "hidden, covered," from Latinized form of Greek kalyptein "to cover, conceal," from PIE root *kel- (1) "to cover, conceal, save."
calyx (n.) Look up calyx at Dictionary.com
"outer part of the perianth of a flower," 1680s, from Latin calyx, from Greek kalyx "seed pod, husk, outer covering" (of a fruit, flower bud, etc.), from root of kalyptein "to cover, conceal," from PIE root *kel- (1) "to cover, conceal, save." The Latin plural is calyces. Some sources connect the word rather with Greek kylix "drinking cup."
cam (n.2) Look up cam at Dictionary.com
abbreviation of camera, by 1990.
cam (n.1) Look up cam at Dictionary.com
1777, "a projecting part of a rotating machinery," from Dutch cam "cog of a wheel," originally "comb;" cognate of English comb (n.). This might have combined with English camber "having a slight arch;" or the whole thing could be from camber. It converts regular rotary motion into irregular, fast-and-slow rotary or reciprocal motion.
camaraderie (n.) Look up camaraderie at Dictionary.com
"companionship, good-fellowship," 1840, from French camaraderie, from camarade "comrade" (see comrade).
camber (n.) Look up camber at Dictionary.com
"convexity on an upper surface," 1610s, nautical term, from Old French cambre, chambre "bent," from Latin camurum (nominative camur) "crooked, arched;" related to camera.
cambium (n.) Look up cambium at Dictionary.com
1670s in botany, "layer of tissue between the wood and the bark," from Late Latin cambium "exchange," from Latin cambiare "change" (see change (v.)).