Online Etymology Dictionary

rampart (n.): 1580s, from Middle French rempart, from remparer "to fortify," from re- "again" (see re-) + emparer "fortify, take possession of," from Old Provençal amparer, from Vulgar Latin *anteparare "prepare," properly "to make preparations beforehand," from Latin ante- "before" (see ante) + parare "prepare" (see pare).
ramrod (n.): 1797, literally "a rod used in ramming," from ram (v.) + rod. The verb is 1948, from the noun. Used figuratively for straightness or stiffness from 1939.
ramshackle (adj.): 1809, back-formation from ramshackled, earlier ranshackled (1670s), alteration of ransackled, past participle of ransackle (see ransack). The word seems to have been regarded as Scottish.
Reading over this note to an American gentleman, he seemed to take alarm, lest the word ramshackle should be palmed on his country. I take it home willingly, as a Scotticism, and one well applied, as may be afterwards shown. [Robert Gourlay, "General Introduction to a Statistical Account of Upper Canada," London, 1822]
Jamieson's "Etymological Dictionary of the Scottish Language" (1825) has it as a noun meaning "thoughtless, ignorant fellow."
ramus: 1803, from Latin ramus "branch," related to radix "root;" see radish.
ran: past tense of run (v.).
ranch (n.): 1808, "country house," from American Spanish rancho "small farm, group of farm huts," from Spanish rancho, originally, "group of people who eat together," from ranchear "to lodge or station," from Old French ranger "install in position," from rang "row, line" (see rank (n.)). Sense of "large cattle-breeding estate" is from 1831. Of houses, "single-story, split-level" from 1950. Ranchero "one employed on a ranch" is from 1826.
rancher (n.): 1836, "owner of a ranch;" see ranch. Meaning "modern single-story house" attested from 1964.
rancid (adj.): 1640s, from Latin rancidus "rank, stinking, offensive," from rancere "be spoiled or rotten," of unknown origin.
rancor (n.): early 13c., from Old French rancor, from Latin rancorem "rancidness, grudge, bitterness," from Latin rancere "to stink" (see rancid).
rancorous (adj.): 1580s, from rancor + -ous. Related: Rancorously; rancorousness.
rancour (n.): chiefly British English spelling of rancor; for ending see -or. Related: Rancourous.
rand (n.): "rocky ridge overlooking a river valley," 1839, South African English, from Afrikaans, from Dutch rand "edge, margin," cognate with Old English rand "brink, bank." As a unit of currency, adopted by the Republic of South Africa in 1961 (see Krugerrand).
Randal: masc. proper name, shortened from Old English Randwulf, from rand "shield" + wulf "wolf." Cf. Randolph.
Randolph: masc. proper name, from Old Norse Rannulfr "shield-wolf" and Frankish *Rannulf "raven-wolf," both brought to England by the Normans.
random (adj.): "having no definite aim or purpose," 1650s, from at random (1560s), "at great speed" (thus, "carelessly, haphazardly"), alteration of Middle English randon "impetuosity, speed" (c.1300), from Old French randon "rush, disorder, force, impetuosity," from randir "to run fast," from Frankish *rant "a running," from Proto-Germanic *randa (cf. Old High German rennen "to run," Old English rinnan "to flow, to run;" see run (v.)).

In 1980s college student slang, it began to acquire a sense of "inferior, undesirable." (A 1980 William Safire column describes it as a college slang noun meaning "person who does not belong on our dormitory floor.") Random access in reference to computer memory is recorded from 1953.
randy (adj.): 1690s, Scottish, "aggressive, boisterous," originally of beggars, later especially of women, probably from rand "to rave" (see rant). Sense of "lewd, lustful" first recorded 1847. Related: Randiness.
range (v.): c.1200, rengen, "move over a large area, roam with the purpose of searching or hunting," from Old French rengier (see range (n.)). Sense of "to arrange in rows" is recorded from c.1300. Related: Ranged; ranging.
range (n.): c.1200, "row or line of persons" (especially hunters or soldiers), from Old French range "range, rank," from rangier "to place in a row, arrange," from reng "row, line" (see rank (n.)). Meaning "row of mountains" is from 1705. Meaning "scope, extent" first recorded 1660s; that of "area over which animals seek food" is from 1620s, from the verb. Specific U.S. sense of "series of townships six miles in width" is from 1785. Sense of "distance a gun can send a bullet" is recorded from 1590s; meaning "place used for shooting practice" is from 1862. The cooking appliance so called since mid-15c., for unknown reasons.
ranger (n.): late 14c., "gamekeeper," agent noun from range (v.)). Attested from 1660s in sense of "man (often mounted) who polices an area." Modern military sense of "member of an elite U.S. combat unit" is attested from 1942 (organized 1941).
rangy (adj.): "having a long, slender form" (as an animal suited to ranging), 1845, from range (v.) + -y (2). Also "adapted for ranging" (1868). Of landscapes, "hilly," 1862, Australian English. Related: Ranginess.
As a rule, we hold that the Jersey should be "growthy," deep-flanked, and loose-jointed, and should have, generally, the characteristics which farmers know as "rangy." ["American Agriculturalist," November 1876]
rank (v.): "arrange things in order, classify," 1580s, from rank (n.). Related: Ranked; ranking.
rank (n.): c.1400, a row of an army, from Old French ranc, from Frankish *hring or some other Germanic source (cf. Old High German hring "circle, ring"), from Proto-Germanic *khrengaz "circle, ring" (see ring (n.)). Meaning "social position" is from early 15c.
rank (adj.): Old English ranc "proud, overbearing, showy," from Proto-Germanic *rankaz (cf. Danish rank "right, upright," German rank "slender," Old Norse rakkr "straight, erect"), perhaps from PIE *reg- "to stretch, straighten" (see right (adj.)).

In reference to plant growth, "vigorous, luxuriant," it is recorded from mid-13c. Sense evolved in Middle English to "large and coarse" (c.1300), then, via notion of "excessive and unpleasant," to "having a strong bad smell" (1520s). Much used 16c. as a pejorative intensive (cf. rank folly). This is possibly the source of the verb meaning "to reveal another's guilt" (1929, underworld slang), and that of "to harass, abuse," 1934, U.S. black dialect, though this also may be from the role of the activity in establishing social hierarchy (from rank (n.)).
rank and file: 1590s, in reference to the horizontal and vertical lines of soldiers marching in formation; thence generalized to "common soldiers" (1796) and "common people" (1860).
rankle (v.): early 14c., from Old French rancler, from draoncle "abscess, festering sore," from Latin dracunculus "little snake," diminutive of draco "serpent, dragon" (see dragon). The notion is of an ulcer caused by a snake's bite. Related: Rankled; rankling.
ransack (v.): mid-13c., from Old Norse rannsaka "to pillage," literally "search the house" (especially legally, for stolen goods), from rann "house," from Proto-Germanic *rasnan (c.f. Gothic razn, Old English ærn "house") + saka "to search," related to Old Norse soekja "seek" (see seek). Sense influenced by sack (v.). Related: Ransacked; ransacking.
ransom (n.): early 13c., "sum paid for the release of a prisoner or captured man," from Old French ranson (Modern French rançon), earlier raenson "ransom, redemption," from Latin redemptionem (nominative redemptio) "a redeeming," from redimere (see redeem).
ransom: c.1300, from ransom (n.). Related: Ransomed; ransoming.
rant (v.): 1590s, from Dutch randten "talk foolishly, rave," of unknown origin (cf. German rantzen "to frolic, spring about"). Related: Ranted; ranting. Ranters "antinomian sect which arose in England c.1645" is attested from 1651; applied 1823 to early Methodists. A 1700 slang dictionary has rantipole "a rude wild Boy or Girl."
rant (n.): 1640s, from rant (v.).
rap (n.): early 14c., "a quick, light blow, stroke," also "a fart" (late 15c.), native or borrowed from a Scandinavian source (cf. Danish rap, Swedish rapp "light blow"); either way probably of imitative origin (cf. slap, clap). Slang meaning "rebuke, blame, responsibility" is from 1777; specific meaning "criminal indictment" (cf. rap sheet, 1960) is from 1903. Meaning "music with improvised words" first in New York City slang, 1979.
rap (v.): mid-14c., "strike, smite, knock," from rap (n.). Meaning "talk informally" is first recorded 1929, popularized c.1965 in Black English, possibly first in Caribbean English, from British slang meaning "say, utter" (1879), originally "to utter a sudden oath" (1540s), ultimately from rap (n.). Meaning "to perform rap music" is recorded by 1979. Related: Rapped; rapping. To rap (someone's) knuckles "give light punishment" is from 1749.
rapacious (adj.): 1650s, from Latin rapaci-, stem of rapax "grasping," from rapere (see rapacity) + -ous. Related: Rapaciously; rapaciousness.
rapacity (n.): 1540s, from Middle French rapacité (16c.), from Latin rapacitatem (nominative rapacitas) "greediness," from rapax "grasping" (genitive rapacis) "plundering," from rapere "seize" (see rapid).
rape (v.): late 14c., "seize prey; abduct, take by force," from Anglo-French raper (Old French rapir) "to seize, abduct," a legal term, probably from past participle of Latin rapere "seize, carry off by force, abduct" (see rapid). Latin rapere was used for "sexual violation," but only very rarely; the usual Latin word being stuprum, literally "disgrace." Meaning "to abduct (a woman), ravish;" also "seduce (a man)" is from early 15c. Related: Raped; raping. Uncertain connection to Low German and Dutch rapen in the same sense.
rape (n.1): "forceful seizure; plundering, robbery, extortion," mid-14c., from Anglo-French rap, rape; see rape (v.). Meaning "act of abducting a woman or sexually assaulting her or both" is from early 15c., but perhaps late 13c. in Anglo-Latin.
rape (n.2): kind of plant (Brassica napus), late 14c., from Old French rape, from Latin rapa, rapum "turnip," from PIE *rap- (cf. Greek hrapys "rape," Old Church Slavonic repa, Lithuanian rope, Middle Dutch roeve, Old High German ruoba, German Rübe "rape, turnip"). Usually grown to feed sheep, an oil made from it is used in cooking (see canola).
Raphael: masc. proper name, Biblical archangel (Apocrypha), from Late Latin, from Greek Hraphael, from Hebrew Rephael, literally "God has healed," from rapha "he healed" + el "God." Raphaelesque (1832) is in reference to painter Raffaello Sanzio (1483-1520). See Pre-Raphaelite.
raphe: "seam, suture" (medical), Modern Latin, from Greek rhaphe "seam, suture (of a skull)," from rhaptein "to sew together, stitch" (see wrap).
rapid (adj.): 1630s, from Latin rapidus "hasty, snatching," from rapere "hurry away, carry off, seize, plunder," from PIE root *reup- "to snatch" (cf. Greek ereptomai "devour," harpazein "snatch away"). Rapid-transit first attested 1852, in reference to street railways; rapid eye movement is from 1906.
rapidity (n.): 1650s, from Latin rapiditatem, from rapidus (see rapid).
rapids (n.): 1765, from French rapides (see rapid); applied by French voyagers to rough, swift-flowing reaches in North American rivers.
rapier (n.): 1550s, from Middle French rapière, from Old French espee rapiere "long, pointed two-edged sword" (late 15c.), in which the adjective is of uncertain origin, perhaps from derisive use of raspiere "poker, scraper."
rapine (n.): early 15c., from Middle French rapine (12c.), from Latin rapina "robbery, plunder," 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," from Old French rapel, from rapeler "to recall, summon" (see repeal). The verb is first recorded 1957. The same word had been borrowed earlier (1848) to mean "a drum roll to summon soldiers."
rapper (n.): agent noun meaning "one who raps" in any sense (see rap (v.)). Before the current performance sense emerged c.1979, it could mean "spirit-rapper" (1755), prison slang for "prosecutor" (1904), "itinerant antiques buyer" (1914, with a tinge of shadiness), "door-knocker" (1630s).
rapport (n.): 1660s, "reference, relationship," from French rapport, back-formation from rapporter "bring back," 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 E.A. Poe).
rapporteur: c.1500, from French rapporteur, from rapporter (see report).