Online Etymology Dictionary

curio (n.): "piece of bric-a-brac from the Far East," 1851, shortened form of curiosity (n.).
curiosity (n.): late 14c., "careful attention to detail," also "desire to know or learn" (originally usually in a bad sense), from Old French curiosete "curiosity, avidity, choosiness" (Modern French curiosité), from Latin curiositatem (nominative curiositas) "desire of knowledge, inquisitiveness," from curiosus (see curious). Neutral or good sense is from early 17c. Meaning "an object of interest" is from 1640s.
curious (adj.): mid-14c., "eager to know" (often in a bad sense), from Old French curios "solicitous, anxious, inquisitive; odd, strange" (Modern French curieux) and directly from Latin curiosus "careful, diligent; inquiring eagerly, meddlesome," akin to cura "care" (see cure (n.)). The objective sense of "exciting curiosity" is 1715 in English. In booksellers' catalogues, the word means "erotic, pornographic." Curiouser and curiouser is from "Alice in Wonderland" (1865).
curium (n.): 1946, named by U.S. chemist Glenn T. Seaborg, who helped discover it in 1944, for the Curies (see Curie).
curl (v.): mid-15c., metathesis of crulle (c.1300), probably from an unrecorded Old English word or from Middle Dutch krul "curly," from Proto-Germanic *krusl- (cf. East Frisian krull "lock of hair," Middle High German krol, Norwegian krull, Danish krølle "curl"). The noun is recorded from c.1600.
curler (n.): 1748, agent noun from curl (v.). Related: Curlers.
curlew (n.): mid-14c., from Old French courlieu (13c., Modern French courlis), said to be imitative of the bird's cry but apparently assimilated with corliu "runner, messenger," from corre "to run" (see current (adj.)). The bird is a good runner.
curlicue (n.): 1843, American English, from curly + cue, perhaps from French queue "tail" or letter Q in its looping script form. Earlier in this sense was curlie-wurlie (1772).
curling (n.): game played with stones on ice, 1610s, from present participle of curl (v.). "The name appears to describe the motion given to the stone" [OED]. A description of a similar game is attested from Flanders c.1600.
curly (adj.): 1770s, from curl + -y (2); earliest use is of hair. Related: Curliness.
curmudgeon (n.): 1570s, of unknown origin; the suggestion, based on a misreading of a garbled note from Johnson, that it is from French coeur mechant "evil heart" is not taken seriously; the first syllable may be cur "dog." Liberman says the word "must have been borrowed from Gaelic (and references muigean "disagreeable person"), with variant spelling of intensive prefix ker-. Related: Curmudgeonly.
currant (n.): c.1500, from raysyn of Curans (mid-14c.) "raisins of Corinth," with the -s- mistaken for a plural inflection. From Anglo-French reisin de Corauntz. The small, seedless raisins were exported from southern Greece. Then in 1570s the word was applied to an unrelated Northern European berry (genus Ribes), recently introduced in England, on its resemblance to the raisins.
currency (n.): 1650s, "condition of flowing," from Latin currens, present participle of currere "to run" (see current (adj.)); the sense of a flow or course extended 1699 (by John Locke) to "circulation of money."
current (adj.): c.1300, "running, flowing," from Old French corant "running, lively, eager, swift," present participle of corre "to run," from Latin currere "to run, move quickly" (of persons or things), from PIE *kers- "to run" (cf. Greek -khouros "running," Lithuanian karsiu "go quickly," Old Norse horskr "swift," Old Irish and Middle Welsh carr "cart, wagon," Breton karr "chariot," Welsh carrog "torrent"). Meaning "prevalent, generally accepted" is from 1560s.
current (n.): late 14c., from Middle French corant (Modern French courant), from Old French corant (see current (adj.)). Applied 1747 to the flow of electrical force.
currently (adv.): "at the present time," 1570s, from current (adj.) + -ly (2).
curricular (adj.): 1798, "pertaining to driving carriages;" from Latin curriculum (see curriculum) + -ar.
curriculum (n.): 1824, from Modern Latin transferred use of classical Latin curriculum "a running, course, career" (also "a fast chariot, racing car"), from currere (see current (adj.)). Used in English as a Latin word since 1630s at Scottish universities.
curriculum vitae (n.): "brief account of one's life and work," 1902, from Latin curriculum vitae, literally "course of one's life" (see curriculum). Abbreviated c.v..
currier (n.): late 14c., "one who dresses and colors leather," from Old French corier, from Latin coriarius "tanner, currier," from corium "hide, leather, skin" (see corium).
curry (v.): late 13c., "to rub down a horse," from Anglo-French curreier "to curry-comb a horse," from Old French correier "put in order, prepare, curry," from con-, intensive prefix (see com-), + reier "arrange," from a Germanic source (see ready). Related: Curried; currying.
curry (n.): the spice, 1680s, from Tamil kari "sauce, relish for rice."
curry favor (v.): early 16c., altered by folk etymology from curry favel (c.1400) from Old French correier fauvel "to be false, hypocritical," literally "to curry the chestnut horse," which in medieval French allegories was a symbol of cunning and deceit. See curry (v.). Old French fauvel is from a Germanic source and ultimately related to fallow (adj.); the sense here is entangled with that of similar-sounding Old French favele "lying, deception," from Latin fabella, diminutive of fabula (see fable (n.)).
curse (n.): late Old English curs "a prayer that evil or harm befall one," of uncertain origin, perhaps from Old French curuz "anger," or Latin cursus "course." Connection with cross is unlikely. No similar word exists in Germanic, Romance, or Celtic. Curses as a histrionic exclamation is from 1885. The curse "menstruation" is from 1930. Curse of Scotland, the 9 of diamonds in cards, is attested from 1791, but the origin is obscure.
curse (v.): Old English cursian, from the source of curse (n.). Meaning "to swear profanely" is from early 13c. Related: Cursed; cursing.
cursive (adj.): 1784, from French cursif (18c.), from Medieval Latin cursivus "running," from Latin cursus "a running," from past participle of currere "to run" (see current (adj.)). The notion is of "written with a running hand" (without raising the pen), as opposed to uncial.
cursor (n.): computer sense is 1967 extension of name for the sliding part of a slide rule or other instrument (1590s), earlier "a running messenger" (c.1300), from Latin cursor "runner," also "errand-boy," from curs-, past participle stem of currere "to run" (see current (adj.)).
cursory (adj.): c.1600, from Middle French cursoire "rapid," from Late Latin cursorius "hasty, of a race or running," from Latin curs-, past participle stem of currere "to run" (see current (adj.)).
curt (adj.): mid-14c., from Latin curtus "(cut) short, shortened, incomplete," from PIE root *(s)ker- "to cut" (see short (adj.)). Sense of "rude" is first recorded 1831. The Latin word was adopted early into most Germanic languages (cf. Icelandic korta, German kurz, etc.) and drove out the native words based on Proto-Germanic *skurt-, but English retains short.
curtail (v.): late 15c., from Middle French courtault "made short," from court "short" (Old French cort, from Latin curtus; see curt) + -ault pejorative suffix of Germanic origin. Originally curtal; used of horses with docked tails, which probably influenced the spelling. Related: Curtailed; curtailing.
curtain (n.): c.1300, from Old French cortine "curtain, tapestry, drape, blanket," from Late Latin cortina "curtain," but in classical Latin "round vessel, cauldron," from Latin cortem (older cohortem) "enclosure, courtyard" (see cohort). The confusion apparently begins in using cortina as a loan-translation for Greek aulaia ("curtain") in the Vulgate (to render Hebrew yeriah in Exodus xxvi:1, etc.) because the Greek word was connected to aule "court," perhaps because the "door" of a Greek house that led out to the courtyard was a hung cloth. The figurative sense in curtain call is from 1884. Curtains "the end" is 1912, originally from stage plays.
curtilage (n.): early 14c., from Anglo-French curtilage, from Old French cortil "little court, walled garden, yard," from Medieval Latin cortile "court, yard," from Latin cortis (see court (n.)).
curtsey: alternative spelling of curtsy.
curtsy (n.): 1540s, "expression of respect," a variant of courtesy (q.v.). Specific meaning "a bending the knee and lowering the body as a gesture of respect" is from 1570s. Originally not exclusively feminine.
curtsy (v.): 1550s, from curtsy (n.). Related: Curtsied; curtsying.
curvaceous (adj.): 1936, U.S. colloquial, from curve + facetious use of -aceous, Modern Latin botanical suffix meaning "of a certain kind." First recorded reference is to Mae West.
curvature (n.): 1660s, from Latin curvatura "a bending," from curvatus, past participle of curvare "to bend" (see curve (v.)). In non-Euclidian geometry, from 1873.
curve (v.): early 15c. (implied in curved), from Latin curvus "crooked, curved, bent," and curvare "to bend," both from PIE root *(s)ker- "to turn, bend" (see ring (n.)).
curve (n.): 1690s, "curved line," from curve (v.). With reference to the female figure (usually plural, curves), from 1862; as a type of baseball pitch, from 1879.
curvilinear (adj.): 1710, from curvi-, comb. form of Latin curvus (see curve (v.)) + linearis, from linea "line" (see line (n.)). Earlier was curvilineal (1650s).
curvy (adj.): 1902, from curve (n.) + -y (2). Related: Curviness.
cushion (n.): c.1300, from Old French coissin "seat cushion" (12c., Modern French coussin), probably a variant of Vulgar Latin *coxinum, from Latin coxa "hip, thigh," or from Latin culcita "mattress." Someone has counted more than 400 spellings of the plural of this word in Middle English wills and inventories. Also from the French word are Italian cuscino, Spanish cojin.
cushion (v.): 1730s, from cushion (n.). In the figurative sense, from 1863. Related: Cushioned; cushioning.
cushy (adj.): "easy," 1915, Anglo-Indian slang, from Hindi khush "pleasant, healthy, happy" + -y (2).
cusp (n.): 1580s, from Latin cuspis "point, spear, pointed end, head," of unknown origin. Astrological use is earliest.
cuspid (n.): 1743, from Latin cuspis (genitive cuspidus) "point, pointed end" (see cusp). Of teeth, from 1878. Related: Cuspidate (adj.), attested from 1690s.
cuspidor (n.): 1779, a colonial word, from Portuguese cuspidor "spittoon," from cuspir "to spit," from Latin conspuere "spit on," from com-, intensive prefix (see com-), + spuere "to spit" (see spew).
cuss (n.): 1775, American English dialectal, "troublesome person or animal," an alteration of curse (n.), or else a shortening of the slang sense of customer.
cuss (v.): "to say bad words," 1815, alteration of curse (v.). Related: Cussed; cussing. To cuss out attested by 1881.
custard (n.): mid-14c., "meat or fruit pie," crustade, from Middle French croustade (Modern French coutarde), from Old Provençal croustado "fruit tart," literally "something covered with crust," from crosta "crust," from Latin crusta (see crust (n.)). Modern meaning is c.1600. Spelling change perhaps by influence of mustard.