Online Etymology Dictionary

cum: verb and noun, by 1973, apparently a variant of the sexual sense of come that originated in pornographic writing, perhaps first in the noun sense. This "experience sexual orgasm" slang meaning of come (perhaps originally come off) is attested from 1650, in "Walking In A Meadowe Greene," in a folio of "loose songs" collected by Bishop Percy.
They lay soe close together, they made me much to wonder;
I knew not which was wether, until I saw her under.
Then off he came, and blusht for shame soe soon that he had endit;
Yet still she lies, and to him cryes, "one more and none can mend it."
As a noun meaning "semen or other product of orgasm" it is on record from the 1920s. The sexual cum seems to have no connection with Latin cum, the preposition meaning "with, together with," which is occasionally used in English in local names of combined parishes or benifices (such as Chorlton-cum-Hardy), in popular Latin phrases (such as cum laude), or as a combining word to indicate a dual nature or function (such as slumber party-cum-bloodbath).
cum laude: 1872, originally at Harvard, from Medieval Latin, literally "with praise," from Latin cum "with" + laude, ablative of laus (genitive laudis) "praise" (see laud). Probably from earlier use (in Latin) at Heidelberg and other German universities.
Cumaean (adj.): 1731, from Latin Cumae (Greek Kyme), ancient city on the Italian coast near Naples, founded by Greeks 8c. B.C.E.; especially famous for the Sybil there, mentioned by Virgil.
cumber (v.): c. 1300, "to overthrow, destroy; to be overwhelmed; to harass," apparently from French, but Old French combrer "to seize hold of, lay hands on, grab, snatch, take by force, rape," has not quite the same sense. Perhaps a shortened formation from a verb akin to Middle English acombren "obstructing progress," from Old French encombrer, from combre "obstruction, barrier," from Vulgar Latin *comboros "that which is carried together," perhaps from a Gaulish word.

The likely roots are PIE *kom (see com-) + *bher- (1) "to bear" (see infer). Weakened sense of "to hamper, to obstruct or weigh down" is late 14c. Related: Cumbered; cumbering.
Cumberland: Old English Cumbra land (945) "region of the Cymry" (see Cymric).
cumbersome (adj.): late 14c., from cumber (v.) + -some (1). Meaning "unwieldy, hard to carry" is from 1590s. Related: Cumbersomely; cumbersomeness.
cumbrous (adj.): late 14c., "cumbersome, troublesome, clumsy, unwieldy," from cumber + -ous.
cumin (n.): Old English cymen, from Latin cuminum, from Greek kyminon, cognate with Hebrew kammon, Arabic kammun.
cummerbund (n.): 1610s, from Hindi kamarband "loin band," from Persian kamar "waist" + band "something that ties," from Avestan banda- "bond, fetter," from PIE root *bhendh- "to bind" (see bend (v.)).
cummin (n.): alternative spelling of cumin.
cumulate (v.): 1530s, from Latin cumulatus "heaped, increased, augmented," past participle of cumulare "to heap," from cumulus "mound, heap" (see cumulus). Related: Cumulated; cumulating.
cumulation (n.): 1610s, noun of action from cumulate.
cumulative (adj.): c. 1600, from Latin cumulatus, past participle of cumulare "to heap," from cumulus "heap" (see cumulus) + -ive.
cumulonimbus (n.): 1887, from cumulo-, comb. form of cumulus, + nimbus.
cumulus (n.): 1650s, "a heap," from Latin cumulus "a heap, pile, mass, surplus," from PIE *ku-m-olo-, suffixed shortened form of root *keue- "to swell" (compare Sanskrit svayati "swells up, is strong," Greek kyein "to swell," Lithuanian šaunas "firm, solid, fit, capable"). Meteorological use for "rounded mass of clouds" first attested 1803.
cun (v.): "to learn to know, inquire into," from Old English cunnian "to learn to know," ultimately from the same ancient root as can (v.1). Surviving into 17c. and perhaps later in dialects.
cuneiform (adj.): 1670s, "wedge shaped," from French cunéiforme (16c.), from Latin cuneus "a wedge, wedge-shaped thing," which is of unknown origin, + French -forme (see form (n.)). Applied to characters in ancient Middle Eastern inscriptions made with wedge-shaped writing tools; first used in this sense by German physician and traveler Engelbert Kämpfer (1681-1716); in English from 1818. As a noun from 1862.
cunnilingus (n.): 1887, from Latin cunnus "vulva" (see cunt) + lingere "to lick" (see lick (v.)). The Latin properly would mean "one who licks a vulva," but it is used in English in reference to the action, not the actor. The verb ought to be *cunnilingue. As an agent-noun, Fletcher has lick-twat (1656). Gordon Williams ["A Dictionary of Sexual Language and Imagery in Shakespearean and Stuart Literature," 1994] writes that Nicolas Chorier's 17c. "Satyra Sotadica" "relates how Gonsalvo of Cordova, as an old man, would lick his mistress's middle parts, which he called, with a geographical pun, going to Liguria" (from Latin ligurio "to lick").
Cunnilingus was a very familiar manifestation in classical times; ... it tends to be especially prevalent at all periods of high civilization. [Havelock Ellis, 1905]
cunning (adj.): early 14c., "learned, skillful," present participle of cunnen "to know" (see can (v.1)). Sense of "skillfully deceitful" is probably late 14c. As a noun from c. 1300. Related: Cunningly.
cunt (n.): "female intercrural foramen," or, as some 18c. writers refer to it, "the monosyllable," Middle English cunte "female genitalia," by early 14c. (in Hendyng's "Proverbs" -- ʒeve þi cunte to cunni[n]g, And crave affetir wedding), akin to Old Norse kunta, Old Frisian, Middle Dutch, and Middle Low German kunte, from Proto-Germanic *kunton, which is of uncertain origin. Some suggest a link with Latin cuneus "wedge," others to PIE root *geu- "hollow place," still others to PIE *gwen-, root of queen and Greek gyne "woman."

The form is similar to Latin cunnus "female pudenda" (also, vulgarly, "a woman"), which is likewise of disputed origin, perhaps literally "gash, slit," from PIE *sker- (1) "to cut," or literally "sheath," from PIE *kut-no-, from root *(s)keu- "to conceal, hide."
Hec vulva: a cunt. Hic cunnus: idem est. [from Londesborough Illustrated Nominale, c. 1500, in "Anglo-Saxon and Old English Vocabularies," eds. Wright and Wülcker, vol. 1, 1884]
First known reference in English apparently is in a compound, Oxford street name Gropecuntlane cited from c. 1230 (and attested through late 14c.) in "Place-Names of Oxfordshire" (Gelling & Stenton, 1953), presumably a haunt of prostitutes. Used in medical writing c. 1400, but avoided in public speech since 15c.; considered obscene since 17c.

in Middle English also conte, counte, and sometimes queinte, queynte (for this, see q). Chaucer used quaint and queynte in "Canterbury Tales" (late 14c.), and Andrew Marvell might be punning on quaint in "To His Coy Mistress" (1650).
"What eyleth yow to grucche thus and grone? Is it for ye wolde haue my queynte allone?" [Wife of Bath's Tale]
Under "MONOSYLLABLE" Farmer lists 552 synonyms from English slang and literature before launching into another 5 pages of them in French, German, Italian, Spanish, and Portuguese. [A sampling: Botany Bay, chum, coffee-shop, cookie, End of the Sentimental Journey, fancy bit, Fumbler's Hall, funniment, goatmilker, heaven, hell, Itching Jenny, jelly-bag, Low Countries, nature's tufted treasure, parenthesis, penwiper, prick-skinner, seminary, tickle-toby, undeniable, wonderful lamp, and aphrodisaical tennis court, and, in a separate listing, Naggie. Dutch cognate de kont means "a bottom, an arse," but Dutch also has attractive poetic slang ways of expressing this part, such as liefdesgrot, literally "cave of love," and vleesroos "rose of flesh."

Alternative form cunny is attested from c. 1720 but is certainly much earlier and forced a change in the pronunciation of coney (q.v.), but it was good for a pun while coney was still the common word for "rabbit": "A pox upon your Christian cockatrices! They cry, like poulterers' wives, 'No money, no coney.' " [Philip Massinger: "The Virgin-Martyr," Act I, Scene 1, 1622]
cup (n.): Old English cuppe, from Late Latin cuppa "cup" (source of Italian coppa, Spanish copa, Old French coupe "cup"), from Latin cupa "tub, cask, tun, barrel," from PIE *keup- "a hollow" (source also of Sanskrit kupah "hollow, pit, cave," Greek kype "a kind of ship," Old Church Slavonic kupu, Lithuanian kaupas).

The Late Latin word was borrowed throughout Germanic: Old Frisian kopp "cup, head," Middle Low German kopp "cup," Middle Dutch coppe, Dutch kopje "cup, head." German cognate Kopf now means exclusively "head" (compare French tête, from Latin testa "potsherd"). Meaning "part of a bra that holds a breast" is from 1938. [One's] cup of tea "what interests one" (1932), earlier used of persons (1908), the sense being "what is invigorating."
cup (v.): late 14c., "to draw blood by cupping," from cup (n.). Meaning "to form a cup" is from 1830. Related: Cupped; cupping.
cupboard (n.): late 14c., "a board or table to place cups and like objects," from cup (n.) + board (n.1). As a type of closed cabinet for food, etc., from early 16c.
cupcake (n.): 1828, American English, from cup (n.) + cake (n.), probably from the cups they are baked in, but possibly from the small measures of ingredients used to make them. Meaning "attractive young woman" is recorded from 1930s, American English.
cupful (n.): mid-12c., from cup (n.) + -ful.
Cupid: Roman god of passionate love, late 14c., from Latin Cupido, personification of cupido "desire, love," from cupere "to desire" (see cupidity). Identified with Greek Eros. Cupid's bow as a shape, especially of lips, is from 1858.
cupidity (n.): mid-15c., from Anglo-French cupidite, Middle French cupidité, from Latin cupiditatem (nominative cupiditas) "passionate desire, lust; ambition," from cupidus "eager, passionate," from cupere "to desire" (perhaps cognate with Sanskrit kupyati "bubbles up, becomes agitated," Old Church Slavonic kypeti "to boil," Lithuanian kupeti "to boil over"). Despite the primarily erotic sense of the Latin word, in English cupidity originally, and still especially, means "desire for wealth."
cupola (n.): 1540s, from Italian cupola, from Late Latin cupula "a little tub," diminutive of Latin cupa "cask, barrel" (see cup (n.)).
cuppa (n.): colloquial shortening of cup of (coffee, etc.), recorded from 1925; as a stand-alone (almost always with implied tea) it dates from 1934.
cupreous (adj.): 1660s, from Late Latin cupreus "of copper," from cuprum, alternative form of cyprum "copper" (see copper (n.1)). Related: Cupric (1799).
cur (n.): early 13c., curre, earlier kurdogge used of both vicious dogs and cowardly dogs, probably from Old Norse kurra or Middle Low German korren both echoic, both meaning "to growl." Compare Swedish dialectal kurre, Middle Dutch corre "house dog."
curable (adj.): late 14c., from cure (v.) + -able; or from Old French curable (13c.) and directly from Late Latin curabilis, from Latin curare.
Curacao: West Indian island, Curaçao, discovered 1499 by Alonso de Hojeda, who called it Isla de los Gigantes in reference to the stature of the natives. The modern name probably is a Europeanized version of some lost native word. The liqueur is made from the dried peel of the Curaçao orange.
curare (n.): 1777, from Portuguese or Spanish curare, a corruption of the name in the Carib language of the Macusi Indians of Guyana, wurali or wurari, which had a sort of click sound at the beginning, and is said to mean "he to whom it comes falls."
curate (n.): late 14c., "spiritual guide," from Medieval Latin curatus "one responsible for the care (of souls)," from Latin curatus, past participle of curare "to take care of" (see cure (v.)). Church of England sense of "paid deputy priest of a parish" first recorded 1550s.
curation (n.): late 14c., from Old French curacion "treatment of illness," from Latin curationem (nominative curatio), "a taking care, attention, management," especially "medical attention," noun of action from past participle stem of curare "to cure" (see cure (v.)).
curative (adj.): early 15c., from Old French curatif (15c.) "curative, healing," from Latin curat-, past participle stem of curare "to cure" (see cure (v.)). As a noun, attested from 1857.
curator (n.): mid-14c., from Latin curator "overseer, manager, guardian," agent noun from curatus, past participle of curare (see cure (v.)). Originally of those put in charge of minors, lunatics, etc.; meaning "officer in charge of a museum, library, etc." is from 1660s.
curb (n.): late 15c., "strap passing under the jaw of a horse" (used to restrain the animal), from Old French courbe (12c.) "curb on a horse," from Latin curvus, from curvare "to bend" (see curve (v.)). Meaning "enclosed framework" is from 1510s, probably originally with a notion of "curved;" extended to margins of garden beds 1731; to "margin of stone between a sidewalk and road" 1791 (sometimes spelled kerb). Figurative sense of "a check, a restraint" is from 1610s.
curb (v.): 1520s, of horses, "to lead to a curb," from curb (n.). Figurative use from 1580s. Related: Curbed; curbing.
curbstone (n.): 1791, from curb (n.) + stone (n.).
curcumin (n.): coloring matter, 1850, from Curcuma, genus name for plants of the ginger family, from which the chemical was drawn, Medieval Latin, from Arabic kurkum "saffron, tumeric." Compare crocus.
curd (n.): c. 1500, metathesis of crud (late 14c.), originally "any coagulated substance," probably from Old English crudan "to press, drive," from PIE root *greut- "to press, coagulate," perhaps via ancestor of Gaelic gruth (because cognates are unknown in other Germanic or Romance languages).
curdle (v.): 1630s (earlier crudle, 1580s), "to thicken, cause to congeal," frequentative of curd (v.) "to make into curd" (late 14c.; see curd). Of blood, in figurative sense "to inspire horror" from c. 1600. Related: Curdled (1590); curdling (c. 1700, almost always with reference to blood, in the figurative sense).
cure (n.1): c. 1300, "care, heed," from Latin cura "care, concern, trouble," with many figurative extensions, such as "study; administration; a mistress," and also "means of healing, remedy," from Old Latin coira-, a noun of unknown origin. Meaning "medical care" is late 14c.
cure (v.): late 14c., from Old French curer, from Latin curare "take care of," hence, in medical language, "treat medically, cure" (see cure (n.1)). In reference to fish, pork, etc., first recorded 1743. Related: Cured; curing.

Most words for "cure, heal" in European languages originally applied to the person being treated but now can be used with reference to the disease, too. Relatively few show an ancient connection to words for "physician;" typically they are connected instead to words for "make whole" or "tend to" or even "conjurer." French guérir (with Italian guarir, Old Spanish guarir) is from a Germanic verb stem also found in in Gothic warjan, Old English wearian "ward off, prevent, defend" (see warrant (n.)).
cure (n.2): parish priest, from French curé (13c.), from Medieval Latin curatus (see curate).
cure-all (n.): "panacea," 1870, from cure (v.) + all. As a name of various plants, it is attested from 1793.
Curetes: from Latin Curetes, from Greek Kouretes, plural of Koures, literally "youthful," related to koros "youth, child."
curettage (n.): 1897; see curette (q.v.) + -age.