rub-a-dub (n.) Look up rub-a-dub at Dictionary.com
1787, echoic of the sound of a drum.
rub-down (n.) Look up rub-down at Dictionary.com
1885, from verbal phrase, from rub (v.) + down (adv.).
rubaiyat (n.) Look up rubaiyat at Dictionary.com
"quatrains" (in Persian poetry), 1859, plural of rubai, from Arabic rubaiyah, from rubaiy "composed of four elements."
rubato Look up rubato at Dictionary.com
musical instruction, 1883, Italian, short for tempo rubato, literally "robbed time," from past participle of rubare "to steal, rob" (see rob (v.)).
rubber (n.) Look up rubber at Dictionary.com
"thing that rubs" (a brush, cloth, etc.), 1530s, agent noun from rub (v.). The meaning "elastic substance from tropical plants" (short for India rubber) first recorded 1788, introduced to Europe 1744 by Charles Marie de la Condamine, so called because it originally was used as an eraser.
Very useful for erasing the strokes of black lead pencils, and is popularly called rubber, and lead-eater. [entry for Caoutchouc in Howard, "New Royal Encyclopedia," 1788]
Meaning "overshoe made of rubber" is 1842, American English; slang sense of "condom" is by 1930s. Sense of "deciding match" in a game or contest is 1590s, of unknown signification, and perhaps an entirely separate word. Rubber stamp (n.) is from 1881; figurative sense of "institution whose power is formal but not real" is from 1919; the verb in this sense is from 1934. Rubber cement is attested from 1856 (from 1823 as India-rubber cement). Rubber check (one that "bounces") is from 1927.
rubberneck (n.) Look up rubberneck at Dictionary.com
1897, "person who is always listening to other people's conversation; person who gazes around him with undue curiosity," from rubber + neck (n.). Popularized with reference to sightseers in automobiles. As a verb from 1896. Related: Rubbernecking (1896); rubbernecker (1934).
rubbers (n.) Look up rubbers at Dictionary.com
see rubber (n.).
rubbery (adj.) Look up rubbery at Dictionary.com
1890, from rubber (n.) + -y (2). Related: Rubberiness.
rubbish (n.) Look up rubbish at Dictionary.com
c.1400, robous, from Anglo-French rubouses (late 14c.), of unknown origin. No apparent cognates in Old French; apparently somehow related to rubble (see OED). Spelling with -ish is from late 15c. The verb sense of "disparage, criticize harshly" is first attested 1953 in Australian and New Zealand slang. Related: Rubbished; rubbishing.
rubble (n.) Look up rubble at Dictionary.com
"rough, irregular stones broken from larger masses," late 14c., robeyl, from Anglo-French *robel "bits of broken stone," probably related to rubbish [OED], but also possibly from Old French robe (see rob).
rube (n.) Look up rube at Dictionary.com
1896, reub, from shortened form of masc. proper name Reuben (q.v.), which is attested from 1804 as a conventional type of name for a country man.
Rube Goldberg (adj.) Look up Rube Goldberg at Dictionary.com
1940, from the U.S. cartoonist Reuben Lucius Goldberg (1883-1970) who devised fantastically complex gadgetry to accomplish simple tasks. His British counterpart was Heath Robinson (1872-1944).
rubella (n.) Look up rubella at Dictionary.com
"German measles," 1883, Modern Latin, literally "rash," from neuter plural of Latin rubellus "reddish," diminutive of ruber "red" (see red (adj.1)).
Rubenesque (adj.) Look up Rubenesque at Dictionary.com
of a woman's body, "rounded and alluringly plump," 1904, of the type characteristic of the paintings of Flemish painter Sir Peter Paul Rubens (1577-1640).
Rubicon (n.) Look up Rubicon at Dictionary.com
in phrase to cross (or pass) the Rubicon "take a decisive step," 1620s, a reference to a small stream to the Adriatic on the coast of northern Italy which in ancient times formed part of the southern boundary of Cisalpine Gaul; crossed by Caesar Jan. 10, 49 B.C.E., when he left his province to attack Pompey. The name is from Latin rubicundus "ruddy," in reference to the color of the soil on its banks.
rubicund (adj.) Look up rubicund at Dictionary.com
"inclining to redness," c.1500, from Middle French rubicond (14c.), or directly from Latin rubicundus, from rubere "to be red," from ruber "red" (see red (adj.1)). Related: Rubicundity.
Rubik's Cube (n.) Look up Rubik's Cube at Dictionary.com
1980, named for teacher Ernö Rubik (b.1944) who patented it in Hungary in 1975.
ruble (n.) Look up ruble at Dictionary.com
unit of the Russian monetary system, 1550s, via French rouble, from Russian rubl', perhaps from Old Russian rubiti "to chop, cut, hew," so called because the original metallic currency of Russia (14c.) consisted of silver bars, from which the necessary amount was cut off; from Proto-Slavic *rub-, from PIE root *reub-, *reup- "to snatch" (see rip (v.)).
rubric (n.) Look up rubric at Dictionary.com
c.1300, "directions in religious services" (often in red writing), from Old French rubrique, rubriche "rubric, title" (13c.), from Latin rubrica "red ochre, red coloring matter," from ruber, from PIE root *rudhro- (see red). Meaning "title or heading of a book" is from early 15c. Related: Rubrical.
ruby (n.) Look up ruby at Dictionary.com
"clear rich-red variety of corundum," c.1300, from Old French rubi (12c.), from Medieval Latin rubinus lapis "red stone" (source also of Italian rubino), from Latin rubeus "red," related to ruber (see red). As a color name from 1570s. As an adjective from late 15c. Modern French rubis is not explained; Klein suggests a plural mistaken for singular.
ruche (n.) Look up ruche at Dictionary.com
"frill," 1827, from French ruche, literally "beehive" (13c.), of Celtic origin (compare Breton rusken), from Proto-Celtic *rusca "bark." Related: Ruched; ruching.
rucksack (n.) Look up rucksack at Dictionary.com
1866, from German Rucksack, from Alpine dialect Rück "the back" (from German Rücken; see ridge) + Sack "sack" (see sack (n.1)).
ruckus (n.) Look up ruckus at Dictionary.com
1890, possibly a blend of ruction and rumpus.
ruction (n.) Look up ruction at Dictionary.com
"disturbance," 1825, dialectal or colloquial, of unknown origin. Perhaps from eruption or an altered shortening of insurrection.
rudder (n.) Look up rudder at Dictionary.com
Old English roðor "paddle, oar," from Proto-Germanic *rothru- (cognates: Old Frisian roðer, Middle Low German roder, Middle Dutch roeder, Dutch roer, Old High German ruodar, German Ruder "oar"), from *ro- "steer" (see row (v.)) + suffix -þra, used to form neutral names of tools. Meaning "broad, flat piece of wood attached to the stern of a boat and used for steering" is from c.1300. Spelling with -d- for -th- first recorded mid-15c. (compare feather (n.), mother (n.), gather).
ruddock (n.) Look up ruddock at Dictionary.com
"robin," late Old English rudduc, from rudu "red color," related to read (see red (adj.1)) + diminutive suffix.
ruddy (adj.) Look up ruddy at Dictionary.com
late Old English rudig "rubicund," probably from rudu "redness," related to read "red" (see red (adj.1)). As a British slang euphemism for bloody (q.v.), first recorded 1914. Related: Ruddiness.
rude (adj.) Look up rude at Dictionary.com
late 13c., "coarse, rough" (of surfaces), from Old French ruide (13c.) or directly from Latin rudis "rough, crude, unlearned," perhaps related to rudus "rubble." Sense of "ill-mannered, uncultured; uneducated, uncultured" is from mid-14c. Rude boy (also rudie, for short) in Jamaican slang is attested from 1967. Figurative phrase rude awakening is attested from 1895.
rudely (adv.) Look up rudely at Dictionary.com
mid-14c., from rude (adj.) + -ly (2).
rudesby (n.) Look up rudesby at Dictionary.com
"insolent person," 1560s, mock surname from rude + -by, common place-name (and thus surname) ending element, as in Grimsby, Rigby. Similar formations in idlesby, sneaksby "paltry, sneaking fellow" (1570s), suresby.
rudiment (n.) Look up rudiment at Dictionary.com
1540s, from Middle French rudiment (16c.) or directly from Latin rudimentum "early training, first experience, beginning, first principle," from rudis "unlearned, untrained" (see rude). Related: Rudiments.
rudimentary (adj.) Look up rudimentary at Dictionary.com
1827; see rudiment + -ary. Earlier was rudimental (1590s).
Rudolph Look up Rudolph at Dictionary.com
masc. proper name, from German Rudolf, from Old High German Hrodulf, literally "fame-wolf," from hruod- "fame, glory" + wolf.
Rudra Look up Rudra at Dictionary.com
storm god in Vedic mythology, from Sanskrit Rudrah, according to Klein literally "the howler, roarer," from stem of rudati "weeps, laments, bewails," cognate with Latin rudere "to roar, bellow," Lithuanian rauda "wail, lamentation," Old English reotan "to wail, lament."
rue (v.) Look up rue at Dictionary.com
"feel regret," Old English hreowan "make sorry, distress, grieve" (class II strong verb; past tense hreaw, past participle hrowen), from Proto-Germanic *khrewan (cognates: Old Frisian riowa, Middle Dutch rouwen, Old Dutch hrewan, German reuen "to sadden, cause repentance"); in part, blended with Old English weak verb hreowian "feel pain or sorrow," and perhaps influenced by Old Norse hryggja "make sad," both from Proto-Germanic *khruwjan, all from PIE root *kreue- (2) "to push, strike" (see anacrusis). Related: Rued; ruing.
rue (n.1) Look up rue at Dictionary.com
perennial evergreen shrub, late 14c., from Old French rue (13c.), earlier rude, from Latin ruta "rue," probably from Greek rhyte, of uncertain etymology, originally a Peloponnesian word. The bitter taste of its leaves led to many punning allusions to rue (n.2.).
rue (n.2) Look up rue at Dictionary.com
"sorrow, repentance," Old English hreow "grief, repentance, sorrow, regret, penitence," common Germanic (Frisian rou, Middle Dutch rou, Dutch rouw, Old High German (h)riuwa, German reue), related to the root of rue (v.).
rue (n.3) Look up rue at Dictionary.com
French for "street," from Vulgar Latin *ruga (source also of Old Italian ruga), properly "a furrow," then in Medieval Latin "a path, street" (see rough (adj.)).
rueful (adj.) Look up rueful at Dictionary.com
early 13c., rewfulle, reowfule, from rue (n.2) + -ful. Related: Ruefulness.
ruefully (adv.) Look up ruefully at Dictionary.com
early 13c., reufulike; see rueful + -ly (2).
ruff (n.) Look up ruff at Dictionary.com
kind of large collar, stiffly starched, especially common in the seventeenth century, 1520s, originally in reference to sleeves (of collars, from 1550s), probably a shortened form of ruffle.

Card-playing sense is a separate word, from a former game of that name (1580s), from Middle French roffle, earlier romfle (early 15c.), from Italian ronfa, perhaps a corruption of trionfo "triumph" (from French; compare trump). The game was in vogue c.1590-1630.
ruff (v.) Look up ruff at Dictionary.com
in cards, 1760, from ruff (n.). Related: Ruffed; ruffing.
ruffian (n.) Look up ruffian at Dictionary.com
1530s, "a boisterous, brutal fellow, one ready to commit any crime," from Middle French rufian "a pimp" (15c.), from Italian ruffiano "a pander, pimp," of uncertain origin, perhaps from a Germanic source related to rough (adj.), but Dutch roffiaan, German Ruffian are said to be from French. English meaning might have been influenced by similarity of sound to rough. Related: Ruffianly.

The Romanic words (such as Medieval Latin ruffianus, Provençal rufian, Catalan rufia, Spanish rufian) preserve the sense of "protector or owner of whores." For sense evolution in English, compare bully (n.).
ruffle (v.) Look up ruffle at Dictionary.com
early 14c., "to disturb the smoothness of," perhaps from Old Norse hrufla "to scratch," or Low German ruffelen "to wrinkle, curl," both of unknown origin. Meaning "disarrange" (hair or feathers) first recorded late 15c.; sense of "annoy, distract" is from 1650s. Related: Ruffled; ruffling.
ruffle (n.) Look up ruffle at Dictionary.com
"ornamental frill," 1707, from ruffle (v.).
rufous (adj.) Look up rufous at Dictionary.com
"reddish-brown," 1782, from Latin rufus "red, reddish, red-haired," from Osco-Umbrian cognate of Latin ruber "red" (see red (adj.1)).
Rufus Look up Rufus at Dictionary.com
masc. proper name, literally "red-haired," from Latin rufus (see rufous).
rug (n.) Look up rug at Dictionary.com
1550s, "coarse fabric," of Scandinavian origin; compare Norwegian dialectal rugga "coarse coverlet," from Old Norse rogg "shaggy tuft," from Proto-Germanic *rawwa-, perhaps related to rag (n.) and rough (adj.). Sense evolved to "coverlet, wrap" (1590s), then "mat for the floor" (1808). Meaning "toupee" is theater slang from 1940. Cut a rug "dance" is slang first attested 1942. To sweep (something) under the rug in the figurative sense is from 1954.
rugae (n.) Look up rugae at Dictionary.com
plural of ruga (1775), from Latin ruga "a wrinkle in the face," from PIE *rug-, variant of *reue- (2) "to smash, knock down, tear up, dig up, uproot" (see rough (adj.)).
rugby (n.) Look up rugby at Dictionary.com
type of football, 1864, after Rugby, public school where the game was played, from city of Rugby in Warwickshire, central England. The place name is Rocheberie (1086), probably "fortified place of a man called *Hroca;" with second element from Old English burh (dative byrig), replaced by 13c. with Old Norse -by "village" due to the influence of Danish settlers. Otherwise it might be *Rockbury today. Or first element perhaps is Old English hroc "rook." Rugby Union formed 1871. Slang rugger for "rugby" is from 1893.