Online Etymology Dictionary

rumple (v.): c.1600, possibly a variant of rimple "to wrinkle" (14c.), from Old English hrympel; possibly influenced by Middle Dutch rumpelen. Related: Rumpled; rumpling.
rumpus (n.): 1764, of unknown origin, possibly an alteration of robustious "boisterous, noisy" (1540s; see robust). First record of rumpus room "play room for children in a family home" is from 1938.
run (v.): the modern verb is a merger of two related Old English words. The first is rinnan, irnan (strong, intransitive, past tense ran, past participle runnen), from Proto-Germanic *renwanan (cf. Middle Dutch runnen, Old Saxon, Old High German, Gothic rinnan, German rinnen "to flow, run"), both from PIE *ri-ne-a-, nasalized form of root *reie- "to flow, run" (see Rhine). The sense of "cause to run" is from Old English ærnan, earnan (weak, transitive, probably a metathesis of *rennan), from Proto-Germanic *rannjanan, causative of the root *ren- "run."

Of streams, etc., from c.1200; of machinery, from 1560s. Meaning "to be in charge of" is first attested 1861, originally American English. Meaning "to seek office in an election" is from 1826, American English. Phrase run for it "take flight" is attested from 1640s. Most figurative uses are from horseracing or hunting (cf to run (something) into the ground, 1836, American English), except (to feel) run down (1901) which is from clocks (in the literal sense, 1761). To run across "meet" is attested from 1855, American English. To run short "exhaust one's supply" is from 1752; to run out of in the same sense is from 1713.
run (n.): "spell of running," mid-15c. (earlier ren, late 14c.), from run (v.). Sense of "small stream" first recorded 1580s, mostly Northern English dialect and American English. Meaning "series or rush of demands on a bank, etc." is first recorded 1690s. Baseball sense is from 1856. Meaning "single trip by a railroad train" is from 1857. Military aircraft sense is from 1916. Meaning "total number of copies printed" is from 1909. Meaning "tear in a knitted garment" is from 1922. Phrase a run for one's money is from 1872 in a figurative sense, originally from horse racing, implying competition (1841). Run-in "quarrel, confrontation" is from 1905.
run-of-the-mill (adj.): "unspectacular," 1909 in a literal sense, in reference to material yielded by a mill, etc., before sorting for quality. Figurative use is from 1922.
runaround (n.): "deceptive, evasive treatment," 1915, from run (v.) + around. The verbal phrase run around "to associate" (with) is from 1887.
runaway (n.): 1540s, from run (v.) + away.
runcible: 1871, a nonsense word coined by Edward Lear; used especially in runcible spoon "spoon with three short tines like a fork," which first took the name 1926.
rundown (n.): in baseball sense, first recorded 1908, from run (v.) + down (adv.). Meaning "list of entries in a horse race and the odds" is from 1935; slang sense of "summary, account, list of information or facts" is from 1945.
rune (n.): Old English run, rune "secret, mystery, dark mysterious statement," also "a runic letter," from Proto-Germanic *runo (cf. Old Norse run "a secret, magic sign, runic character," Old High German runa "a secret conversation, whisper," Gothic runa), from PIE *ru-no-, source of technical terms of magic in Germanic and Celtic. The word entered Middle English as roun and by normal evolution would have become Modern English *rown, but it died out mid-15c. when the use of runes did. The modern usage is from 1680s, introduced by German philologists from a Scandinavian source (cf. Danish rune, from Old Norse run). The runic alphabet is believed to have developed by 2c. C.E. from contact with Greek writing, the alphabet modified to be more easily cut into wood or stone. Cf. also Runnymede.
rung (n.): Old English hrung "rod, bar," from Proto-Germanic *khrungo (cf. Middle Low German runge, Old High German runga "stake, stud, stave," Middle Dutch ronghe, Dutch rong "rung," Gothic hrugga "staff"), of unknown origin with no connections outside Germanic. Sense in English narrowed to "round or stave of a ladder" (first attested late 13c.), but usage of cognate words remains more general in other Germanic languages.
runic (adj.): 1660s, from Modern Latin runicus, from Old Norse run (see rune).
runnel (n.): "rivulet," 1570s, in Hakluyt, from Old English rinelle, a diminutive form related to rinnan "to run" (see run (v.)).
runner (n.): c.1300, agent noun from run (v.). Meaning "smuggler" first recorded 1721; sense of "embroidered cloth for a table" is from 1888.
runner-up (n.): 1842, originally in dog racing; see runner + up. General sense is from 1885.
running (n.): verbal noun from run (v.); to be in (or out) of the running "among" (or "not among") "the lead competitors in a race" (1863) is a metaphor from horse racing, where make the running "set the pace" is recorded from 1837.
running (adj.): present participle adjective from run (v.). Running mate originally was a horse entered in a race to set the pace for another from the same stable who was intended to win (1865); U.S. vice-presidential sense is recorded from 1888. Running dog first recorded 1937, from Chinese and North Korean communist phrases used to describe supposed imperialist lackeys, cf. Mandarin zou gou "running dog," on the notion of a dog that runs at its master's command. Running board first attested 1817, in reference to ships and boats.
runny (adj.): 1817, from run (v.) + -y (2).
Runnymede: place in Surrey where the Magna Charta was signed, Middle English Ronimede, literally "meadow on the council island," from Old English runieg "council island," from run in sense of "council" (see rune).
runoff (n.): also run-off, "precipitation water drained by streams and rivers," 1887, from run (v.) + off. Meaning "deciding race after a tie" is from 1873; electoral sense is attested by 1910, American English.
runt (n.): c.1500, "old or decayed tree stump," of unknown origin. Meaning extended to "small ox or cow" (1540s) and by 1610s to other animals and people. Specific American English sense of "smallest of a litter" (especially of pigs) is attested from 1841. Some see a connection to Middle Dutch runt "ox," but OED thinks this unlikely, and pronounces the word "of obscure origin."
runway (n.): 1833, "customary track of an animal," especially a deer, American English, from run (v.) + way. Meaning "artificial sloping track" is attested from 1883; airfield sense is from 1923.
rupee (n.): Indian coin, 1610s, from Hindi or Urdu rupiyah, from Sanskrit rupyah "wrought silver," originally "something provided with an image, a coin," from rupah "shape, likeness, image."
Rupert: masc. proper name, probably a blend of German Ruprecht and English Robert.
rupture (n.): early 15c., originally medical, from Latin ruptura "the breaking (of an arm or leg), fracture," from past participle stem of rumpere "to break," cognate with Old English reafian "to seize, rob, plunder," reofan "to tear, break;" Old Norse rjufa "to break" (see reft).
rupture (v.): 1739, from rupture (n.). Related: Ruptured; rupturing.
rural (adj.): early 15c., from Old French rural (14c.), from Latin ruralis "of the countryside," from rus (genitive ruris) "open land, country," from PIE *rur- "open space" (cf. Old Church Slavonic ravinu "level," Old Irish roi, roe "plain field," Old English rum "space;" see room).
In early examples, there is usually little or no difference between the meanings of rural and rustic, but in later use the tendency is to employ rural when the idea of locality (country scenes, etc.) is prominent, and rustic when there is a suggestion of the more primitive qualities or manners naturally attaching to country life. [OED]
Ruritanian (adj.): "utopian," 1896, from Ruritania, name of an imaginary kingdom in "The Prisoner of Zenda" (1894) by Anthony Hope (1863-1933), who coined it from Latin rus (genitive ruris) "country" (see rural) + Latinate ending -itania (cf. Mauritania).
ruse (n.): early 15c., "dodging movements of a hunted animal," from Old French ruse (14c.), noun use of ruser "to dodge, repel, retreat," from Latin recusare "deny, reject, oppose," from re- intensive prefix, + causari "plead as a reason, object, allege," from causa "reason, cause." Or the French word may be from Latin rursus "backwards." "A French word neither elegant nor necessary." [Johnson] But the verb ruse was used in Middle English.
rush (n.2): late 14c., from rush (v.). Sense of "mass migration of people" (especially to a gold field) is from 1848, American English. Meaning "surge of pleasure" is from 1960s. Rush hour first recorded 1888.
rush (v.): mid-14c. (implied in rushing), "to drive back or down," from Anglo-French russher, from Old French ruser "to dodge, repel" (see ruse). Meaning "to do something quickly" is from 1650s; transitive sense of "to hurry up (someone or something)" is from 1850. Football sense originally was in rugby (1857). Fraternity/sorority sense is from 1896 (originally it was what the fraternity did to the student).
rush (n.1): "plant growing in marshy ground," Old English resc, earlier risc, from Proto-Germanic *rusk- (cf. Middle Low German rusch, Middle High German rusch, West Frisian risk).

Old French rusche probably is from a Germanic source. Used for making torches and finger rings, also strewn on floors when visitors arrived; it was attested a type of "something of no value" from c.1300.
rusk (n.): "light, crisp bits of bread or biscuit," 1590s, from Spanish or Portuguese rosca "roll, twist of bread," literally "coil, spiral," of unknown origin, perhaps from a pre-Latin Iberian word.
Russell: masc. proper name, from Old French rous-el, diminutive of rous "red," used as a personal name.
russet (n.): mid-13c., "cloth of reddish-brown color" (sense of the color itself is first recorded early 15c.), from Old French rousset, from rosset (adj.) "reddish," diminutive of ros, rous "red," from Latin russus, which is related to ruber "red," from PIE *reudh- "red" (see red). As a color name, attested from 1530s. The word was first applied to a type of apples 1620s, to a type of pears 1725.
Russia: 1530s, from Medieval Latin Russi "the people of Russia," from Rus, the native name of the people and the country (cf. Arabic Rus, Medieval Greek Rhos), originally the name of a group of Swedish merchant/warriors who established themselves around Kiev 9c. and founded the original Russian principality; perhaps from Ruotsi, the Finnish name for "Sweden," from Old Norse Roþrslandi, old name of Roslagen "the land of rowing," where the Finns first encountered the Swedes. Or perhaps related to the IE root for "red," in reference to hair color. Russian city-states were founded and ruled by Vikings and their descendants. The Russian form of the name, Rossiya, appears to be from Byzantine Greek Rhosia. Russification is from 1842.
Russian: 1530s (n.), from Medieval Latin Russianus, from Russia (see Russia). Slang or colloquial Russki "Russian" (1858) is from Russian Russkiy. Russian roulette attested from 1937. Russian dressing for salads is from 1915.
rust (v.): early 13c., from rust (n.). As a plant disease, attested from mid-14c. Related: Rusted; rusting.
rust (n.): Old English rust, related to rudu "redness," from Proto-Germanic *rusta- (cf. Frisian rust, Old High German and German rost, Middle Dutch ro(e)st), from PIE *reudh-s-to- (cf. Lithuanian rustas "brownish," rudeti "to rust;" Latin robigo, Old Church Slavonic ruzda "rust"), from root *reudh- "red" (see red (1)). Rust Belt "dacayed urban industrial areas of mid-central U.S." (1984) was popularized, if not coined, by Walter Mondale's presidential campaign.
rustic (adj.): mid-15c., from Latin rusticus, from rus (genitive ruris) "open land, country" (see rural). Noun meaning "a country person, peasant" is from mid-16c.
rusticate (v.): 1650s, from Latin rusticatus, past participle of rusticarti "to live in the country" (see rustication). Related: Rusticated; rusticating.
rustication (n.): 1620s, from Latin rusticationem (nominative rusticatio) "act or fact of living in the country," noun of action from past participle stem of rusticari "live or stay in the country," from rusticus (see rustic).
rustle (v.): "to emit soft, rapid sounds," late 14c. (implied in rustling), of uncertain origin, perhaps imitative (cf. Middle Low German ruschen, Middle Dutch ruusscen, German rauschen "to rustle"). Related: Rustled; rustling. Meaning "steal" (especially cattle) first attested 1882, probably from earlier American English slang sense of "move about vigorously" (1872), perhaps a separate word, compounded from rush and hustle.
rustle (n.): 1759, from rustle (v.).
rusty (adj.): Old English rustig, from rust (see rust). Cognate with Frisian roastich, Middle Dutch roestich, Old High German rostag, German rostig. "In the 16th and 17th centuries frequently used as a term of general disparagement" [OED]. Of skills, accomplishments, etc., first attested 1796.
rut (n.1): "track," 1570s, probably from Middle English route (see route); though OED finds this "improbable." Metaphoric meaning "narrow, monotonous routine" first attested 1839.
rut (n.2): "animal mating season" (originally of deer), early 15c., from Old French rut, ruit, from Late Latin rutigum (nominative rugitus) "a bellowing," from past participle of Latin rugire "to bellow." The verb is recorded from 1620s. Related: Rutting.
rutabaga (n.): 1799, from Swedish dialectal (W. Götland) rotabagge, from rot "root" + bagge "bag." Slang meaning "dollar" is from 1940s.
Ruth: fem. proper name, biblical ancestor of David, from Hebrew Ruth, probably a contraction of reuth "companion, friend, fellow woman."
Ruthenian (adj.): 1850, of or pertaining to the Ukrainian people (earlier Ruthene, 1540s), from Medieval Latin Rutheni "the Little Russians," a derivative of Russi (see Russia). For consonant change, cf. Medieval Latin Prut(h)eni, from Prussi "Prussians."