Online Etymology Dictionary

rapine (n.): early 15c., "plunder," from Middle French rapine (12c.), from Latin rapina "act of robbery, plundering, pillage," from rapere "seize, carry off, rob" (see rapid).
rapist (n.): 1883, agent noun from rape (v.).
rapparee (n.): "Irish freebooter," 1680s, originally "pikeman," from Irish rapairidhe, plural of rapaire "half-pike." Kind of soldier prominent in the war of 1688-92.
rappel (n.): 1931, "mountaineering technique for descending steep faces," from French rappel, literally "recall" (Old French rapel), from rapeler "to recall, summon" (see repeal (v.)). The same word had been borrowed earlier (1848) to mean "a drum roll to summon soldiers."
rappel (v.): 1957 in the mountaineering sense; see rappel (n.). Related: Rappeled; rappelling.
rapper (n.): agent noun meaning "one who raps" in any sense (see rap (v.)). Before the hip-hop performance sense emerged c. 1979, it could mean "door-knocker" (1630s), "spirit-rapper" (1755), "professional perjurer" (1840), prison slang for "prosecutor" (1904), "itinerant antiques buyer," with a tinge of shadiness (1914). Rapster is from 1772.
rapping (n.): c. 1400, verbal noun from rap (v.1). Meaning "talking" is from 1969; meaning "rap music performance" is from 1979, from rap (v.2).
rapport (n.): 1660s, "reference, relation, relationship," from French rapport "bearing, yield, produce; harmony, agreement, intercourse," back-formation from rapporter "bring back; refer to," from re- "again" (see re-) + apporter "to bring," from Latin apportare "to bring," from ad- "to" (see ad-) + portare "to carry" (see port (n.1)).

Psychological meaning "intense harmonious accord," as between therapist and patient, is first attested 1894, though the word had been used in a very similar sense with reference to mesmerism from 1845 (first recorded in Poe). See also report (n.). Johnson frowns on the word and credits its use in English to Sir William Temple, naturalizer of French terms, who did use it but was not the first to do so.
rapportage (n.): "the describing of events in writing," 1903, from French rapportage, literally "tale-telling," from rapporter (see rapport).
rapporteur (n.): c. 1500, from French rapporteur "tell-tale, gossip; reporter," from rapporter (see report (n.)).
rapprochement (n.): "establishment of cordial relations," 1809, from French rapprochement "reunion, reconciliation," literally "a bringing near," from rapprocher "bring near," from re- "back, again" (see re-) + aprochier (see approach (v.)).
rapscallion (n.): 1690s, alteration of rascallion (1640s), a fanciful elaboration of rascal (q.v.). It had a parallel in now-extinct rampallion (1590s), from Middle English ramp (n.2) "ill-behaved woman."
rapt (adj.): late 14c., "carried away in an ecstatic trance," from Latin raptus, past participle of rapere "seize, carry off" (see rape (v.)). A figurative sense, the notion is of "carried up into Heaven (bodily or in a dream)," as in a saint's vision. Latin literal sense of "carried away" was in English from 1550s. In 15c.-17c. the word also sometimes could mean "raped." Sense of "engrossed" first recorded c. 1500. As a past participle adjective, in English it spawned the back-formed verb rap "to affect with rapture," which was common c. 1600-1750.
raptor (n.): c. 1600, "ravisher, abductor," from Latin raptor "a robber, plunderer, abductor, ravisher," agent noun from past participle stem of rapere "to seize" (see rapid). Ornithological use is from 1873 (1823 in Latin plural Raptores).
raptorial (adj.): "predatory," 1825, from raptor + -ial. Alternative raptatorial "predacious" (1840) is from Latin raptatus, past participle of raptare.
rapture (n.): c. 1600, "act of carrying off," from Middle French rapture, from Medieval Latin raptura "seizure, rape, kidnapping," from Latin raptus "a carrying off, abduction, snatching away; rape" (see rapt). Earliest attested use in English is of women and in 17c. it sometimes meant rape (v.), which word is a cognate of this. Sense of "spiritual ecstasy, state of mental transport" first recorded c. 1600 (raptures).
rapture (v.): 1630s, from rapture (n.). Related: Raptured; rapturing.
rapturous (adj.): 1670s, from rapture + -ous. Related: Rapturously (1660s).
rara avis (n.): c. 1600, "peculiar person," from Latin rara avis, literally "strange bird," from rara, fem. of rarus "rare" (see rare (adj.1)) + avis "bird" (see aviary). Latin plural is raræ aves. Horace's peacock (a Roman delicacy), Juvenal's black swan ("Rara avis in terris, nigroque simillima cygno").
rare (adj.1): "unusual," late 14c., "thin, airy, porous;" mid-15c., "few in number and widely separated, sparsely distributed, seldom found;" from Old French rere "sparse" (14c.), from Latin rarus "thinly sown, having a loose texture; not thick; having intervals between, full of empty spaces," from PIE *ra-ro-, from root *ere- "to separate; adjoin" (source also of Sanskrit rte "besides, except," viralah "distant, tight, rare;" Old Church Slavonic rediku "rare," Old Hittite arhaš "border," Lithuanian irti "to be dissolved"). "Few in number," hence, "unusual." Related: Rareness. In chemistry, rare earth is from 1818.
rare (adj.2): "undercooked," 1650s, variant of Middle English rere, from Old English hrere "lightly cooked," probably related to hreran "to stir, move, shake, agitate," from Proto-Germanic *hrorjan (source also of Old Frisian hrera "to stir, move," Old Saxon hrorian, Dutch roeren, German rühren, Old Norse hroera), from PIE root *kere- "to mix, confuse; cook" (source also of Greek kera- "to mix," krasis "mixture"). Originally of eggs, not recorded in reference to meat until 1784, and according to OED, in this sense "formerly often regarded as an Americanism, although it was current in many English dialects ...."
rare (v.): "rise up," 1833, dialectal variant of rear (v.1). Sense of "eager" (in raring to go) first recorded 1909. Related: Rared; raring.
rarebit (n.): 1785, perversion of (Welsh) rabbit, as if from rare (adj.) + bit (n.). See Welsh.
raree show: "peep show contained in a box," 1680s, so called "in imitation of the foreign way of pronouncing rare show" [Johnson]. "Johnson's statement is prob. correct; the early exhibitors of peep-shows appear to have been usually Savoyards, from whom the form was no doubt adopted" [OED]. Early "peep shows" were more innocent than what usually was meant later by that word.
rarefaction (n.): c. 1600, from Middle French raréfaction or directly from Medieval Latin rarefactionem (nominative rarefactio), noun of action from past participle stem of Latin rarefacere (see rarefy). Used chiefly in reference to gases.
rarefy (v.): late 14c., from Old French rarefier (14c.) and directly from Medieval Latin rarificare, from Latin rarefacere "make rare," from rarus "rare, thin" (see rare (adj.1)) + facere "to make" (see factitious). Related: Rarefied.
rarely (adv.): 1550s, from rare (adj.1) + -ly (2). "Seldom, not often;" also "finely, excellently."
rarify (v.): common but incorrect spelling of rarefy (q.v.). Related: Rarified; rarifying.
rarity (n.): early 15c., "thinness;" 1550s, "fewness," from Middle French rarité or directly from Latin raritas "thinness, looseness of texture; fewness," from rarus (see rare (adj.1)). Sense of "a rare thing or event" is from 1590s.
ras: Ethiopian title, from Amharic ras "chief, head," from Arabic ra's.
rascal (n.): mid-14c., rascaile "people of the lowest class, rabble of an army," also singular, "low, tricky, dishonest person," from Old French rascaille "rabble, mob" (12c., Modern French racaille, "the rascality or base and rascall sort, the scumme, dregs, offals, outcasts, of any company" [Cotgrave, French-English Dictionary, 1611]), perhaps a diminutive from Old French rascler, from Vulgar Latin *rasicare "to scrape" (see rash (n.)). Used also in Middle English of animals not hunted as game.
rascality (n.): "low and vulgar people collectively," 1570s; "character of a rascal," 1590s, from rascal + -ity.
rascally (adj.): "low, mean, unprincipled," from rascal + -ly (1).
rase (v.): late 14c., "remove by scraping, rub, scrape out, erase," from Old French raser "to scrape, shave," from Medieval Latin rasare, frequentative of Latin radere (past participle rasus) "to scrape, shave," perhaps from PIE *razd- (source also of Latin rastrum "rake"), possible extended form of root *red- "to scrape, scratch, gnaw" (see rodent). Related: Rased; rasing.
rash (adj.): late 14c., "nimble, quick, vigorous" (early 14c. as a surname), a Scottish and northern word, perhaps from Old English -ræsc (as in ligræsc "flash of lightning") or one of its Germanic cognates, from Proto-Germanic *raskuz (source also of Middle Low German rasch, Middle Dutch rasc "quick, swift," German rasch "quick, fast"). Related to Old English horsc "quick-witted." Sense of "reckless, impetuous, heedless of consequences" is attested from c. 1500. Related: Rashly; rashness.
rash (n.): "eruption of small red spots on skin," 1709, perhaps from French rache "a sore" (Old French rasche "rash, scurf"), from Vulgar Latin *rasicare "to scrape" (also source of Old Provençal rascar, Spanish rascar "to scrape, scratch," Italian raschina "itch"), from Latin rasus "scraped," past participle of radere "to scrape" (see raze). The connecting notion would be of itching. Figurative sense of "any sudden outbreak or proliferation" first recorded 1820.
rasher (n.): "thin slice of bacon or ham," 1590s, of unknown origin. Perhaps from Middle English rash "to cut," variant of rase "to rub, scrape out, erase." However, early lexicographer John Minsheu explained it in 1627 as a piece "rashly or hastily roasted."
Raskolnik: "dissenter from the Russian Church, an Old Believer," 1723, from Russian Raskolnik "separatist," from raskol "schism, separation." The schism was a result of reforms by Patriarch Nikon in 1667.
rasp (v.): mid-13c., "to scrape," from Middle Dutch raspen and from Old French rasper (Modern French râper) "to grate, rasp," which is perhaps from a West Germanic source (compare Old English gehrespan) akin to the root of raffle. Vocalic sense is from 1843. Related: Rasped; rasping.
rasp (n.): "coarse file," 1540s, from Middle French raspe (Modern French râpe), from Old French rasper "to rasp" (see rasp (v.)).
raspberry (n.): 1620s, earlier raspis berry (1540s), possibly from raspise "a sweet rose-colored wine" (mid-15c.), from Anglo-Latin vinum raspeys, origin uncertain, as is the connection between this and Old French raspe, Medieval Latin raspecia, raspeium, also meaning "raspberry." One suggestion is via Old Walloon raspoie "thicket," of Germanic origin. Klein suggests it is via the French word, from a Germanic source akin to English rasp (v.), with an original sense of "rough berry," based on appearance.

A native plant of Europe and Asiatic Russia, the name was applied to a similar vine in North America. Meaning "rude sound" (1890) is shortening of raspberry tart, rhyming slang for fart.
Rasputin: acquired name (Russian, literally "debauchee") of Grigory Yefimovich Novykh (c. 1872-1916), mystic and faith healer who held sway over court of Nicholas II of Russia. His nickname is from his doctrine of "rebirth through sin," that true holy communion must be preceded by immersion in sin. His name used figuratively in English from 1937 for anyone felt to have an insidious and corrupting influence.
raspy (adj.): 1670s, of plants; by 1821 of voices, from rasp + -y (2).
Rasta (adj.): 1955; see Rastafarian. From 1962 as a noun. Related: Rastaman.
Rastafarian (n.): 1955 (Rastafarite is found from 1953), from Rastafari, Jamaican religion built around writings of Marcus Garvey and belief that Haile Selassie (1892-1975), former emperor of Ethiopia, was God. From Ras Tafari, Selassie's title from 1916 to his accession in 1936, from Amharic ras "chief, head" (from Arabic ra's) + tafari "to be feared." As an adjective from 1960.
Rastafarianism: 1964, from Rastafarian + -ism. Rastafarism is attested from 1955.
rastaquouere (n.): 1883, from French rastaquouère, rastacouère (19c.) "social intruder, upstart" (especially one of exaggerated manners and dress, from a Mediterranean or South American country), thus "dashing but untrustworthy foreigner." Short form rasta attested from 1905. According to French sources, the word is from South American Spanish rastacuero "upstart," from arrastrar "to drag, pull, tow, trail along the ground" + cuero "leather." Arrastrar is said to be from Spanish rastro "rake," from Latin rastrum (see raster), while cuero is from Latin corium (see corium).
raster (n.): 1934 in electrical engineering, from German Raster "screen, frame," from Latin rastrum "rake," from rasum, from rodere "to scrape" (see raze). Related: Rasterization; rasterize. From Latin form rastellum comes French râteau "rake," formerly ratel, originally rastel.
Rastus: also 'Rastus, masc. proper name, short for Erastus. As a stereotypical name of an American slave or derogatory for "black man," 1881, probably from use in stories of Joel Chandler Harris.
rat (n.): late Old English ræt "rat," of uncertain origin. Similar words are found in Celtic (Gaelic radan), Romanic (Italian ratto, Spanish rata, French rat) and Germanic (Old Saxon ratta; Dutch rat; German Ratte, dialectal Ratz; Swedish råtta, Danish rotte) languages, but connection is uncertain and origin unknown. In all this it is very much like cat.

Perhaps from Vulgar Latin *rattus, but Weekley thinks this is of Germanic origin, "the animal having come from the East with the race-migrations" and the word passing thence to the Romanic languages. American Heritage and Tucker connect Old English ræt to Latin rodere and thus PIE *red- "to scrape, scratch, gnaw," source of rodent (q.v.). Klein says there is no such connection and suggests a possible cognate in Greek rhine "file, rasp." Weekley connects them with a question mark and Barnhart writes, "the relationship to each other of the Germanic, Romance, and Celtic words for rat is uncertain." OED says "probable" the rat word spread from Germanic to Romanic, but takes no position on further etymology.
RATS. Of these there are the following kinds: a black rat and a grey rat, a py-rat and a cu-rat. ["Dictionary of the Vulgar Tongue," Grose, 1788]
Middle English common form was ratton, from augmented Old French form raton. Sense of "one who abandons his associates" (1620s) is from belief that rats leave a ship about to sink or a house about to fall and led to meaning "traitor, informant" (1902; verb 1910). Interjection rats is American English, 1886. To smell a rat is 1540s; "to be put on the watch by suspicion as the cat by the scent of a rat; to suspect danger" [Johnson]. _____-rat, "person who frequents _____" (in earliest reference dock-rat) is from 1864.