Larger font
Smaller font
Etymology dictionary - Contents
  • Results
  • Related
  • Featured
No results found for: "".
  • Weighted Relevancy
  • Content Sequence
  • Relevancy
  • Earliest First
  • Latest First
    Larger font
    Smaller font


    R — radula (n.)


    eighteenth letter of the English alphabet, traceable to Phoenician and always representing more or less the same sound, which in many languages is typically so resonant and continuous as to be nearly akin to the vowels, but in English is closer to -l-.ETD R.2

    It was aspirated at the start of words (hr-) in Old English, as in Greek, but this was abandoned in English spelling and pronunciation by the end of the Old English period, but the rh- spelling survives in many words borrowed from Greek. In many languages and some dialects (e.g. Scottish) it is pronounced with a distinct trilling vibration of the tongue-tip, which gave it its ancient nickname of "the dog letter;" in other regional dialects (e.g. Boston) it is omitted unless followed by a vowel, while in others it is introduced artificially in pronunciation ("idear," "drawring").ETD R.3

    Louise Pound ("The Humorous 'R'") notes that in British humorous writing, -ar- "popularly indicates the sound of the vowel in father" and formations like larf (for laugh) "are to be read with the broad vowel but no uttered r."ETD R.4

    She also quotes Henry James on the characteristic prominence of the medial -r- sound (which tends to be dropped in England and New England) in the speech of the U.S. Midwest, "under some strange impulse received toward consonantal recovery of balance, making it present even in words from which it is absent, bringing it in everywhere as with the small vulgar effect of a sort of morose grinding of the back teeth."ETD R.5

    In a circle, meaning "registered (trademark)," attested by 1925. R&R "rest and relaxation," is attested by 1953, American English; R&B "rhythm and blues" (type of popular music) is attested by 1949, American English. Form three Rs, see Three Rs.ETD R.6


    "hawk-headed sovereign sun god of Egyptian mythology," from Egyptian R' "sun, day."ETD Ra.2


    Ethiopian title of chief ministers, generals, governors, etc., from Amharic ras "chief, head," from Arabic ra's.ETD ras.2


    Moroccan capital, from Arabic ar-ribat, from ribat "fortified monastery."ETD Rabat.2

    rabbet (n.)

    "rectangular groove or channel cut out of the edge of a board or piece of stone so that it will join by overlapping with the next piece, similarly cut," late 14c., rabet, from Old French rabat "a recess in a wall, a lower section," literally "a beating down or back," a back-formation from rabattre "to beat down, beat back" (see rebate (v.); the noun is a doublet of this word).ETD rabbet (n.).2

    The verb, meaning "to groove or fit (boards, etc.) by cutting rabbets" is attested from mid-15c. (implied in rabatted, rabetynge); Middle English also had rabet "joiner's plane, rabbet-plane" (mid-15c., from Old French rabot).ETD rabbet (n.).3

    rabbi (n.)

    "Jewish doctor of religious law," early 14c. (in late Old English in biblical context only, as a form of address); in Middle English as a title prefixed to personal names, also "a spiritual master" generally; from Late Latin rabbi, from Greek rhabbi, from Mishnaic Hebrew rabbi "my master."ETD rabbi (n.).2

    This is formed from -i, first person singular pronominal suffix, + rabh "master, great one," title of respect for Jewish doctors of law. This is from the Semitic root r-b-b "to be great or numerous" (compare robh "multitude;" Aramaic rabh "great; chief, master, teacher;" Arabic rabba "was great," rabb "master").ETD rabbi (n.).3

    rabbinical (adj.)

    "pertaining to rabbis or their language, learning, or opinions," 1620s, earlier rabbinic (1610s); see rabbi + -ical. The -n- is perhaps via rabbin "rabbi" (1520s), an alternative form, from French rabbin or directly from Medieval Latin rabbinus (also source of Italian rabbino, Spanish and Portuguese rabino), perhaps from a presumed Semitic plural in -n, or from Aramaic rabban "our teacher," "distinguishing title given to patriarchs and the presidents of the Sanhedrin since the time of Gamaliel the Elder" [Klein], from Aramaic plural of noun use of rabh "great."ETD rabbinical (adj.).2

    rabbinate (n.)

    "dignity or office of a rabbi," 1702, from rabbin "rabbi" (see rabbinical) + -ate (1).ETD rabbinate (n.).2

    rabbit (n.)

    common burrowing mammal, identified as a rodent, noted for prolific breeding, late 14c., rabet, "young of the coney," suspected to be from Walloon robète or a similar northern French dialect word, a diminutive of Flemish or Middle Dutch robbe "rabbit," which are of unknown origin. "A Germanic noun with a French suffix" [Liberman]. The adult was a coney (q.v.) until 18c.ETD rabbit (n.).2

    Rabbit punch "chop on the back of the neck" (1915) is so called from resemblance to a gamekeeper's method of dispatching an injured rabbit. Pulling rabbits from a hat as a conjurer's trick recorded by 1843. Rabbit's foot "good luck charm" is attested by 1879 in U.S. Southern black culture. Earlier references are to its use as a tool to apply cosmetic powders.ETD rabbit (n.).3

    Rabbit-hole is by 1705. Rabbit ears "dipole television antenna" is from 1950. Grose's 1785 "Dictionary of the Vulgar Tongue" has "RABBIT CATCHER. A midwife."ETD rabbit (n.).4

    rabble (n.1)

    c. 1300, "pack of animals" (a sense now obsolete), of uncertain origin, but possibly related to Middle English rablen "to gabble, speak in a rapid, confused manner" (mid-14c.), which is probably imitative of hurry, noise, and confusion (compare Middle Dutch rabbelen, Low German rabbeln "to chatter").ETD rabble (n.1).2

    The meaning "tumultuous crowd of vulgar, noisy people" is from late 14c., probably a back-formation from the Middle English verb. It was applied contemptuously to the common or low part of any populace, regardless of tumult, by 1550s.ETD rabble (n.1).3

    rabble (n.2)

    "iron bar, bent at right angles at one end, for stirring molten metal," 1864, from French râble, from Old French roable, from Latin rutabulum "rake, fire shovel" (in Medieval Latin also rotabulum), from ruere "to churn or plow up, dig out," (from PIE *reuo-, source also of Sanskrit ravisam, ravat "to wound, hurt;" Lithuanian ráuti "to tear out, pull," ravėti "to weed;" Russian ryt'i, roju "to dig," Old Church Slavonic rylo "spade," Old Norse ryja "to tear out wool," German roden "to root out").ETD rabble (n.2).2

    rabble-rouser (n.)

    "demagogue, one who arouses the emotions of a disorderly crowd," 1842, agent noun from rabble-rousing, which is attested by 1802 as an adjective (in Sydney Smith), by 1933 as a noun; see rabble (n.1) + rouse (v.).ETD rabble-rouser (n.).2

    Rabelaisian (adj.)

    1775, "of or pertaining to the writings or style of 16c. French author François Rabelais," whose writings "are distinguished by exuberance of imagination and language combined with extravagance and coarseness of humor and satire." [OED]ETD Rabelaisian (adj.).2

    rabies (n.)

    "extremely fatal infectious disease of dogs, humans, and many other mammals," 1590s, from Latin rabies "madness, rage, fury," related to rabere "be mad, rave" (see rage (v.)). The mad-dog disease sense was a secondary meaning of the Latin noun. Known as hydrophobia (q.v.) in humans. Related: Rabietic.ETD rabies (n.).2

    rabidity (n.)

    1822, "state of being infected with rabies;" 1825, "state of being furious or violently raving;" see rabid + -ity.ETD rabidity (n.).2

    rabid (adj.)

    1610s, "furious, raving, behaving violently," from Latin rabidus "raging, furious, enraged; inspired; ungoverned; rabid," from rabere "be mad, rave" (see rage (v.)). The specific meaning "made mad by rabies" in English is recorded by 1804. Related: Rabidly; rabidness.ETD rabid (adj.).2

    raccoon (n.)

    also racoon, "small plantigrade carnivorous quadruped," common in the warmer parts of North America, c. 1600, arocoun, from Algonquian (Powhatan) arahkun, from arahkunem "he scratches with the hands." Early forms included Capt. John Smith's raugroughcum. In Norwegian, vaskebjørn, literally "wash-bear," from its habit of dipping its food in water before eating it.ETD raccoon (n.).2

    race (v.)

    c. 1200, rasen "to rush," from a Scandinavian source akin to the source of race (n.1), reinforced by the noun in English and by Old English cognate ræsan "to rush headlong, hasten, enter rashly." Transitive meaning "run swiftly" is from 1757. Meaning "run against in a competition of speed" is from 1809. Transitive sense of "cause to run" is from 1860. In reference to an engine, etc., "run with uncontrolled speed," from 1862; transitive sense is by 1932. Related: Raced; racing.ETD race (v.).2

    race (n.1)

    [act of running] late Old English, also rase, "a narrative, an account;" c. 1300, "an act of swift running, a hurried attack," also "a course of life or conduct, a swift current;" from Old Norse rās "a running, a rush (of water)," cognate with Old English ræs "a running, a rush, a leap, jump; a storming, an attack;" or else a survival of the Old English word with spelling and pronunciation influenced by the Old Norse noun and the verb. The Norse and Old English words are from Proto-Germanic *res- (source also of Middle Dutch rasen "to rave, rage," German rasen, Old English raesettan "to rage" (of fire)), from a variant form of PIE *ers- (1) "be in motion" (see err).ETD race (n.1).2

    Originally a northern word, it became general in English c. 1550. Formerly used more broadly than now, of any course which has to be run, passed over, or gone through, such as the course of time or events or a life (c. 1300) or the track of a heavenly body across the sky (1580s). To rue (one's) race (15c.) was to repent the course one has taken.ETD race (n.1).3

    Meaning "contest of speed involving two or more competitors; competitive trial in running, riding, etc." is from 1510s. For the sense of "artificial stream leading water to a mill, etc.," see race (n.3). Meaning "electoral contest for public office" is by 1827.ETD race (n.1).4

    racing (n.)

    "the running of races, the occupation or business of arranging for or carrying on races," originally especially horse races, 1670s, verbal noun from race (v.).ETD racing (n.).2

    race (n.2)

    [people of common descent] 1560s, "people descended from a common ancestor, class of persons allied by common ancestry," from French race, earlier razza "race, breed, lineage, family" (16c.), possibly from Italian razza, which is of unknown origin (cognate with Spanish raza, Portuguese raça). Etymologists say it has no connection with Latin radix "root," though they admit this might have influenced the "tribe, nation" sense, and race was a 15c. form of radix in Middle English (via Old French räiz, räis). Klein suggests the words derive from Arabic ra's "head, beginning, origin" (compare Hebrew rosh).ETD race (n.2).2

    Original senses in English included "wines with characteristic flavor" (1520), "group of people with common occupation" (c. 1500), and "generation" (1540s). The meaning developed via the sense of "tribe, nation, or people regarded as of common stock" to "an ethnical stock, one of the great divisions of mankind having in common certain physical peculiarities" by 1774 (though as OED points out, even among anthropologists there never has been an accepted classification of these). In 19c. also "a group regarded as forming a distinctive ethnic stock" (German, Greeks, etc.).ETD race (n.2).3

    In mid-20c. U.S. music catalogues, it means "Negro." Old English þeode meant both "race, folk, nation" and "language;" as a verb, geþeodan meant "to unite, to join." Race-consciousness "social consciousness," whether in reference to the human race or one of the larger ethnic divisions, is attested by 1873; race-relations is attested by 1897. Race theory "assertion that some racial groups are endowed with qualities deemed superior" is by 1894.ETD race (n.2).4

    race (n.3)

    [strong current of water] c. 1300, more or less a particular sense of race (n.1), which then denoted any forward movement or swift running, from Old Norse ras in its sense of "a rushing of water." Via Norman French the word entered French as ras, which might have given English race its specialized meaning of "channel of a stream" (especially an artificial one, to a mill, etc.), which is recorded in English from 1560s.ETD race (n.3).2

    race-course (n.)

    1764, "plot of ground laid out for horse racing," usually elliptical and with accommodations for participants and spectators, from race (n.1) + course (n.). Meaning "canal along which water is conveyed to or from a water wheel" is by 1841.ETD race-course (n.).2

    race-horse (n.)

    "horse bred or kept for running in contests," 1620s, from race (n.1) + horse (n.).ETD race-horse (n.).2

    racemic (adj.)

    "pertaining to or derived from grapes," 1835, from French racémique, from Latin racemus "cluster of grapes" (see raisin). Related: Racemism; racemation.ETD racemic (adj.).2

    raceme (n.)

    1785, in reference to a type of flower cluster, from Latin racemus "a cluster of grapes" (see raisin). In Middle English, "a raisin or currant" (late 14c.).ETD raceme (n.).2

    racer (n.)

    "one who or that which races," 1640s of persons, 1660s of horses, 1793 of vehicles, by 1809 in American English in reference to a type of snake; agent nouns from race (v.).ETD racer (n.).2

    race-riot (n.)

    "riot resulting from racial hostility," by 1875, American English, from race (n.2) + riot (n.). The thing itself is older; in the Jacksonian era it was comprised in the general term mobbing.ETD race-riot (n.).2

    race-track (n.)

    "a race-course, the path over which a race is run," 1814, from race (n.1) + track (n.).ETD race-track (n.).2

    raceway (n.)

    1828, "artificial passage for water flowing from a fall or dam," from race (n.3) + way (n.). Meaning "automobile race course" is by 1936, from race (n.1).ETD raceway (n.).2


    fem. proper name, biblical daughter of Laban and wife of Jacob, from Late Latin, from Greek Rhakhel, from Hebrew (Semitic) Rahel, literally "ewe" (compare Arabic rahil, Aramaic rahla, Akkadian lahru, a metathesized form).ETD Rachel.2


    also rhachio-, before vowels rachi-, word-forming element meaning "spinal, pertaining to the vertebrae," from Latinized form of Greek rhakhis "spine, back," metaphorically "ridge (of a mountain), rib of a leaf," a word of uncertain origin. Compare Greek rhakhos "thorn hedge."ETD rachio-.2

    rachitic (adj.)

    "afflicted with rickets," 1797, from rachitis (1727), medical Latin name for the bone disease, from Late Greek rhakhitis (nosos) "rachitic (disease), inflammation of the spine," from Greek rhakhis "spine, back," metaphorically "ridge (of a mountain), rib of a leaf" (see rachio-).ETD rachitic (adj.).2

    racy (adj.)

    1650s, "having a characteristic agreeable taste; having a flavor supposed to be imparted by the soil" (of wines, fruits, etc.), from race (n.2) in its older meaning "flavor" or in the sense "class of wines" + -y (2).ETD racy (adj.).2

    The extended meaning "having a quality of vigor" (1660s) led to that of "improper, risqué," attested by 1901, which probably was reinforced by the phrase racy of the soil "earthy" (1870). Related: Racily; raciness.ETD racy (adj.).3

    racialization (n.)

    "process of making or becoming racialist," 1874; see racialist.ETD racialization (n.).2

    racialism (n.)

    1882, "tribalism;" 1890, "political system advocating superiority and exclusive rights based on race," from racial + -ism. Also see racist.ETD racialism (n.).2

    racial (adj.)

    "relating, pertaining to, or characteristic of an ethnic race or race generally," 1862, from race (n.2) + -ial. "A word of considerable frequency in the 20th century" [OED]. Related: Racially.ETD racial (adj.).2

    racialist (n.)

    "a racist, an advocate of racial theory, a believer in the superiority of a particular race," 1910, from racial + -ist. Also see racist. As an adjective from 1917.ETD racialist (n.).2

    raciation (n.)

    "evolutionary development of biological races," by 1946, from race (n.2) + ending from speciation, etc.ETD raciation (n.).2

    racism (n.)

    by 1928, in common use from 1935, originally in a European context, "racial supremacy as a doctrine, the theory that human characteristics and abilities are determined by race;" see racist, and compare the various senses in race (n.2) and racialism. Applied to American social systems from late 1930s.ETD racism (n.).2

    racist (n.)

    1932 (as an adjective from 1938), from race (n.2) + -ist. Racism (q.v.) is in use by 1928, originally in the context of fascist theories, and common from 1936. These words replaced earlier racialism (1882) and racialist (1910), both often used early 20c. in a British or South African context. There are isolated uses of racism from c. 1900.ETD racist (n.).2

    Earlier, race hatred (1852 of the Balkans, 1858 of British India, 1861 of white and black in America), race prejudice (1867 of English in India, 1869 of white and black in America, 1870 of the English toward Irish) were used, and, especially in 19c. U.S. political contexts, negrophobia. Anglo-Saxonism as "belief in the superiority of the English race" had been used (disparagingly) from 1860. Anti-Negro (adj.) is attested in British and American English from 1819.ETD racist (n.).3

    rack (n.1)

    c. 1300, "grating or open frame with bars or pegs upon which things are hung or placed," especially for kitchen use, possibly from Middle Dutch rec "framework," literally "something stretched out, related to recken (modern rekken) "stretch out," cognate with Old English reccan "to stretch out," from Proto-Germanic *rak- (source also of Old Saxon rekkian, Old Frisian reza, Old Norse rekja, Old High German recchen, German recken, Gothic uf-rakjan "to stretch out"), from PIE root *reg- "to move in a straight line."ETD rack (n.1).2

    Or it might have developed from the Old English verb. The sense of "frame on which clothes or skins are stretched to dry" is by early 14c. The sense of "framework above a manger for holding hay or other fodder for livestock" is from mid-14c. As the name of a type of instrument of torture by early 15c., perhaps from German rackbank, originally an implement for stretching leather, etc. Sense of "punishment by the rack" is by 1580s.ETD rack (n.1).3

    Mechanical meaning "metal bar with teeth on one edge" is from 1797 (see pinion). Meaning "set of antlers" is first attested 1945, American English; hence slang sense of "a woman's breasts" (especially if large), by 1991. Meaning "framework for displaying clothes" is from 1948; hence off the rack (1951) of clothing, as opposed to tailored.ETD rack (n.1).4

    rack (n.3)

    [clouds driven before the wind], c. 1300, rak, "movement, rapid movement," also "rush of wind, collision, crash," originally a northern word, possibly from Old English racu "cloud, storm" (or an unrecorded Scandinavian cognate of it), reinforced by Old Norse rek, *rak "wreckage, jetsam," or Old English wræc "something driven," both of which would be from Proto-Germanic *wrakaz, from PIE root *wreg- "to push, shove, drive" (see urge (v.)).ETD rack (n.3).2

    From late 14c. as "rain cloud." Often confused with wrack (n.) "destruction," especially in the phrase rack and ruin (1590s), which perhaps is encouraged in that case by the visual alliteration. Rack is "fragments of raggy clouds;" wrack is, in its secondary sense, "seaweed cast up on shore." Both probably come, ultimately, from the same PIE root, as does wreak.ETD rack (n.3).3

    rack (n.4)

    "cut of animal meat and bones," usually involving the neck and forepart of the spine, 1560s, of unknown origin; perhaps from some resemblance to rack (n.1). Compare rack-bone "vertebrae" (1610s).ETD rack (n.4).2

    rack (v.1)

    early 15c., rakken, "to stretch, stretch out (cloth) for drying," also, of persons, "to torture by violently stretching on the rack," from rack (n.1) or from Middle Dutch or Middle Low German recken. Of other pains from 1580s.ETD rack (v.1).2

    Figurative sense of "subject to strenuous effort" (of the brain, memory, etc.) is by 1580s; that of "to torment, afflict with great pain or distress" is from c. 1600. Meaning "fit with racks" is from 1580s.ETD rack (v.1).3

    Sense of "to place (pool balls, etc.) in a rack" as before starting a game is by 1909 (the noun in this sense is by 1907). Teenager slang meaning "to sleep" is from 1960s (rack (n.) was Navy slang for "bed" in 1940s). Related: Racked; racking. Rack up "register, accumulate, achieve" is attested by 1943 (in Billboard magazine), probably from pool halls, perhaps from a method of keeping score. To rack up formerly was "fill a stable rack with hay or straw for horses kept overnight" (1743).ETD rack (v.1).4

    rack (v.2)

    "to draw off (wine, etc.) from the lees; draw off, as pure liquor, from sediment," late 15c., rakken, from Old French raquer, rëechier, rëequier which is of uncertain origin. Related: Racked, racking.ETD rack (v.2).2

    rack (n.2)

    type of gait of a horse, between a trot and a gallop or canter, 1580s, from rack (v.) "move with a fast, lively gait" (1520s, implied in racking), which is of unknown origin; perhaps from French racquassure "racking of a horse in his pace," itself of unknown origin. Or perhaps a variant of rock (v.1).ETD rack (n.2).2

    racket (n.2)

    "handled paddle or netted bat used in tennis, etc.;" see racquet.ETD racket (n.2).2

    racket (n.1)

    "loud, disorderly, confusing noise," 1560s, probably imitative. Klein and Century Dictionary compare Gaelic racaid "noise, disturbance," but OED says this "is no doubt from Eng."ETD racket (n.1).2

    Meaning "dishonest activity" (1785) is perhaps an extended sense, from the notion of "something going on" or "noise or disturbance made to distract a pick-pocket's victim." Or it might be from racquet, via the notion of "a game," or from or reinforced by rack-rent "extortionate rent." There also was a verb racket "carry on eager or energetic action" (1753), and the gangster sense might be via the notion of "exciting and unusual." Weakened sense of "way of life, one's line of business" is by 1891.ETD racket (n.1).3

    racketeer (n.)

    "member of a criminal gang practicing extortion, 'protection,' intimidation, etc.," 1927, a word from Prohibition, from racket (n.1) in the "dishonest activity" sense + -eer. Earlier (1926) in reference to organizers of fraudulent bankruptcies. By 1928 as a verb. Related: Racketeering, verbal noun (1927).ETD racketeer (n.).2

    rack-rent (n.)

    "extortionate rent, rent raised to the highest possible limit, rent greater than any tenant can be expected to pay," especially of land-rents in Ireland, c. 1600, from rent (n.) + rack (v.1) in the otherwise obsolete sense of "extort or obtain by rapacity, raise (rent, etc.) above a fair level" (1550s).ETD rack-rent (n.).2

    raconteur (n.)

    "storyteller, person given to or skilled in relating anecdotes," 1817, a French word in English, from French raconteur, from raconter "to recount, tell, narrate," from re- (see re-) + Old French aconter "to count, render account" (see account (v.); and compare recount (v.1)). Generally in italics in English until well into 20c. Related: Raconteuse (fem.).ETD raconteur (n.).2

    racquet (n.)

    "handled instrument to strike the ball in tennis, etc.," c. 1500, probably extended from earlier racket "tennis-like game played with open hand" (late 14c.), from Old French rachette, requette, rechete, resquette (Modern French raquette) "racket for hitting; the palm of the hand," which is of uncertain origin.ETD racquet (n.).2

    Perhaps it comes via Italian racchetta or Spanish raqueta, both often said to be from Arabic rāhat, a form of rāha "palm of the hand," but this has been doubted. Compare French jeu de paume "tennis," literally "play with the palm of the hand," and compare tennis.ETD racquet (n.).3

    racquetball (n.)

    game played with racquets and a light ball in an enclosed court, 1972, from racquet + ball (n.1). Earlier, racket-ball was "ball used in a racquet game" (1650s).ETD racquetball (n.).2

    rad (n.)

    1918, "x-ray dose unit," a shortened form of radiation (q.v.). The meaning "unit of absorbed dose of ionizing radiation" is by 1954, an acronym from radiation absorbed dose. As shortened form of radical (n.), it is attested in political slang from 1820. Teen slang adjectival sense of "extraordinary, wonderful" is from late 1970s (see radical (adj.)).ETD rad (n.).2

    radar (n.)

    "electronic system for locating and tracking objects at a distance by means of radio waves," 1941, acronym (more or less) from radio detecting and ranging. The U.S. choice, it won out over British radiolocation. Figurative from 1950.ETD radar (n.).2

    raddle (v.)

    "color coarsely with red or rouge," 1630s, from raddle (n.) "red ochre used as paint, layer of red pigment" (mid-14c.), from rad, a variant of red. Related: Raddled, raddling.ETD raddle (v.).2

    radiative (adj.)

    "having a tendency to radiate," 1820, from radiate (v.) + -ive. Related: Radiativity.ETD radiative (adj.).2

    radial (adj.)

    c. 1400, "of or like a ray or radius," from Medieval Latin radialis, from Latin radius "shaft, rod; spoke of a wheel; beam of light" (see radius). Meaning "arranged like the radii of a circle" is by 1750. As a noun, "a radiating or radial part," by 1872. As a type of tire, attested from 1965, short for radial-ply (tire), so called because the cords run at right angles to the circumference. Related: Radially.ETD radial (adj.).2

    radian (n.)

    "angle subtended at the center of a circle by an arc equal in length to the radius," 1879, from radius.ETD radian (n.).2

    radiance (n.)

    c. 1600, "brilliant light, brightness shooting in diverging rays or beams," from radiant (adj.) or else from Medieval Latin radiantia "brightness," from radiare "to beam, shine" (see radiation). Figurative use, of beauty, joy, etc., is by 1761. Related: Radiancy.ETD radiance (n.).2

    radiant (adj.)

    mid-15c., "shining, bright, shooting or emitting diverging rays of light," later also of heat, from Latin radiantem (nominative radians) "beaming, shining," present participle of radiare "to beam, shine" (see radiation). Of beauty, wit, etc., "sparkling, beaming," attested from c. 1500. Related: Radiantly.ETD radiant (adj.).2

    radiant (n.)

    in optics, "point or object from which light radiates," 1714; see radiant (adj.). In astronomy, of meteor showers, "the point in the heavens from which the shooting stars seem to proceed," by 1834, in reference to the great shower of the previous November.ETD radiant (n.).2

    radiation (n.)

    mid-15c., radiacion, "act or process of emitting light," from Latin radiationem (nominative radiatio) "a shining, radiation," noun of action from past-participle stem of radiare "to beam, shine, gleam; make beaming," from radius "beam of light; spoke of a wheel" (see radius).ETD radiation (n.).2

    Meaning "rays or beams emitted" is from 1560s. Meaning "divergence from a center" is 1650s. In modern physics, "emission or transmission of energy in the form of waves or particles," especially in reference to ionizing radiation, from early 20c.ETD radiation (n.).3

    radiate (v.)

    1610s, "issue or spread in all directions from a point in rays or straight lines," from Latin radiatus, past participle of radiare "to beam, shine, gleam; make beaming," from radius "beam of light; spoke of a wheel" (see radius). Meaning "be radiant, give off rays (of light or heat)" is from 1640s. Related: Radiated; radiates; radiating.ETD radiate (v.).2

    radiate (adj.)

    "having rays, furnished with rays or ray-like parts, shining," 1660s, from Latin radiatus, past participle of radiare "to beam, shine, gleam; make beaming," from radius "beam of light; spoke of a wheel" (see radius).ETD radiate (adj.).2

    radiator (n.)

    1832, "any thing which radiates," agent noun in Latin form from radiate (v.). Originally a stove-like apparatus, as a device designed to communicate heat from steam to a room by 1855; the sense of "cooling device in an internal combustion engine" is by 1899.ETD radiator (n.).2

    radicality (n.)

    "state or character of being radical," in any sense, 1640s, from radical (adj.) + -ity.ETD radicality (n.).2

    radicant (adj.)

    1735, in botany, "bringing forth roots," from Latin radicantem (nominative radicans), present participle of radicare "to take root," from radix "root" (from PIE root *wrād- "branch, root").ETD radicant (adj.).2

    radicalism (n.)

    "state or character of being radical," in any sense, 1819, from radical (adj.) + -ism. Originally, and especially, in the political sense of "holding or carrying out of extreme principles on any subject."ETD radicalism (n.).2

    radically (adv.)

    early 15c., radicali, "originally, from the roots or sources," from radical (adj.) + -ly (2). Sense of "thoroughly" is by c. 1600.ETD radically (adv.).2

    radicalize (v.)

    1820, transitive, "make radical, cause to conform to radical ideals," from radical (adj.) + -ize. Intransitive sense of "become radical" is by 1828. Related: Radicalized; radicalizing.ETD radicalize (v.).2

    radicate (v.)

    "cause to take root," late 15c., from Late Latin radicatus, past participle of radicare "to take root," from radix "root" (from PIE root *wrād- "branch, root"). Middle English had also radicacion (c. 1500) "fact or condition of being rooted."ETD radicate (v.).2

    radicate (adj.)

    "fastened, attached, rooted," early 15c., from Late Latin radicatus, past participle of radicare "to take root," from radix "root" (from PIE root *wrād- "branch, root"). Botanical sense of "having a root" is by 1858.ETD radicate (adj.).2

    radical (n.)

    1630s, in philology, "root part of a word, primitive verbal element serving as the root of inflected or derivative words," from radical (adj.) Political sense of "extremist, person who holds radical principles, one who pursues a theory to its furthest limit" is by 1802; chemical sense is by 1816.ETD radical (n.).2

    radicalness (n.)

    "state of being radical," in any sense, 1650s, from radical (adj.) + -ness.ETD radicalness (n.).2

    radical (adj.)

    late 14c., "originating in the root or ground;" of body parts or fluids, "vital to life," from Latin radicalis "of or having roots," from Latin radix (genitive radicis) "root" (from PIE root *wrād- "branch, root"). The basic sense of the word in all meanings is "pertaining or relating to a root or roots," hence "thoroughgoing, extreme."ETD radical (adj.).2

    The figurative meaning "going to the origin, essential" is from 1650s. The political sense of "reformist" is by 1817, of the extreme section of the British Liberal party (radical reform had been a current phrase since 1786), via the notion of "change from the roots" (see radical (n.)). The meaning "unconventional" is from 1921. U.S. youth slang use is from 1983, from 1970s surfer slang meaning "at the limits of control."ETD radical (adj.).3

    The mathematical radical sign, placed before any quantity to denote that its root is to be extracted, is from 1680s; the sign itself is a modification of the letter -r-. Radical chic is attested from 1970; popularized, if not coined, by Tom Wolfe. Radical empiricism was coined 1897 by William James (see empiricism).ETD radical (adj.).4

    radicand (n.)

    in mathematics, the number under a radical sign, by 1843, from German, from Modern Latin radicandus, gerundive of radicare "to take root," from radix "root" (from PIE root *wrād- "branch, root").ETD radicand (n.).2

    radicle (n.)

    1670s, in botany, "rootlet, part of the embryo of a plant which develops into the primary root," from Latin radicula, diminutive of radix "root" (from PIE root *wrād- "branch, root"). Anatomical sense of "branch of a nerve, vein, etc. resembling a root" is by 1830.ETD radicle (n.).2

    radicular (adj.)

    "belonging to, pertaining to, or affecting roots; characterized by the presence of radicles," by 1815, from radicle or else from Modern Latin radicula, diminutive of Latin radix "root" (from PIE root *wrād- "branch, root") + -ar.ETD radicular (adj.).2


    word-forming element meaning 1. "ray, ray-like" (see radius); 2. "radial, radially" (see radial (adj.)); 3. "by means of radiant energy" (see radiate (v.)); 4. "radioactive" (see radioactive); 5. "by radio" (see radio (n.)).ETD radio-.2

    radio (v.)

    "transmit by radio," 1916, from radio (n.). Related: Radioed; radioing. An earlier verb in the same sense was marconi (1908), from the name of Italian inventor Guglielmo Marconi (1874-1937), pioneer of wireless telegraphy.ETD radio (v.).2

    radio (n.)

    "wireless transmission of voice signals with radio waves," 1907, abstracted or shortened from earlier combinations such as radio-receiver (1903), radiophone "instrument for the production of sound by radiant energy" (1881), radio-telegraphy "means of sending telegraph messages by radio rather than by wire" (1898), from radio- as a combining form of Latin radius "beam" (see radius). Use for "radio receiver" is attested by 1913; sense of "sound broadcasting as a medium" also is from 1913.ETD radio (n.).2

    As late as July 1921 the New York Times was calling it wireless telephony, and wireless remained widespread until World War II, when military preference for radio established it as the word. As an adjective by 1912, "by radio transmission;" meaning "controlled by radio" is from 1974. Radio _______ as the proper name of a particular radio station or service, "radio station or service from _______" is by 1920. A radio shack (1946) was a small outbuilding housing radio equipment.ETD radio (n.).3

    radioactivity (n.)

    "state of being radioactive; emissions from radioactive material or processes," 1899, from French radioactivité, coined 1898 by the Curies; see radioactive.ETD radioactivity (n.).2

    radioactive (adj.)

    1898, of an atomic nucleus, "capable of spontaneous nuclear decay releasing ionizing emissions," from French radio-actif, coined by Pierre and Marie Curie from radio-, combining form of Latin radius "ray" (see radius) + actif "active" (see active). Of processes, etc., "involving or produced by radioactivity," by 1903.ETD radioactive (adj.).2

    radio-carbon (n.)

    "carbon-14," a radioactive isotope of carbon, 1940, from radio-, combining form of radioactive, + carbon. Radio-carbon dating is attested from 1949 (the carbon-14 in organic matter decays at a known rate from the time of death).ETD radio-carbon (n.).2

    radiocast (n.)

    "a radio broadcast," 1924, from radio (n.) + ending from broadcast. As a verb by 1931.ETD radiocast (n.).2

    radiography (n.)

    1896, "science or process of making images of objects on a sensitive plate by means of x-rays," from radiograph, the word for such an image-making device; from radio-, combining form of radiation, + -graph. Radiograph was used earlier as "device to measure and record the intensity of sunshine" (1880).ETD radiography (n.).2

    radioisotope (n.)

    "a radioactive isotope," 1946, from radio-, combining form of radiation, + isotope.ETD radioisotope (n.).2

    radiolarian (n.)

    "one of the Radiolaria," a name applied by Haeckel (1862) to the protozoa called by Ehrenberg Polycystina. The classification name is Modern Latin, from Latin radiolus, diminutive of radius (q.v.), so called for the organisms' radiant "spikes."ETD radiolarian (n.).2

    radiology (n.)

    1900, "medical use of X-rays," later extended to "scientific study of radiation," from radio-, combining form of radiation, + Greek-based scientific suffix -ology. Related: Radiological.ETD radiology (n.).2

    radiometric (adj.)

    "pertaining to the radiometer or to experiments performed by it," 1877, from radiometer "instrument to transform radiant energy into mechanical work" (1875), radiometry, from radio-, here indicating "radiant energy," + -metric. Previously radiometer was the name of an old cross-staff instrument for measuring angles. Radiometric dating is attested from 1906.ETD radiometric (adj.).2

    radioscopy (n.)

    "examination by means of x-rays," 1896, from radio- + -scopy.ETD radioscopy (n.).2

    radio-telephone (n.)

    "telephone link through which the signal is transmitted partly by radio," 1900, from radio (n.) + telephone (n.).ETD radio-telephone (n.).2

    radiotherapy (n.)

    "treatment of disease by means of x-rays," 1902, from radio- + therapy.ETD radiotherapy (n.).2

    radish (n.)

    cruciferous plant cultivated from antiquity for its crisp, slightly pungent, edible root, Middle English radich, from late Old English rædic "radish," from Latin radicem (nominative radix) "root, radish" (from PIE root *wrād- "branch, root"). The spelling in English is perhaps influenced by Old French radise, variant of radice, from Vulgar Latin *radicina, from radicem.ETD radish (n.).2

    radius (n.)

    1590s, "cross-shaft, straight rod or bar," from Latin radius "staff, stake, rod; spoke of a wheel; ray of light, beam of light; radius of a circle," a word of unknown origin. Perhaps related to radix "root," but de Vaan finds that "unlikely." The classical plural is radii.ETD radius (n.).2

    The geometric sense of "straight line drawn from the center of a circle to the circumference" is recorded from 1650s. Meaning "circular area of defined distance around some place" is attested from 1853. As the name of the shorter of the two bones of the forearm from 1610s in English (the Latin word had been used thus by the Romans).ETD radius (n.).3

    radium (n.)

    radioactive metallic alkaline earth element, 1899, from French radium, formed in Modern Latin from Latin radius "ray" (see radius). With metallic element ending -ium. Named 1898 after identification by Marie Curie and her husband; so called for its power of emitting energy in the form of rays.ETD radium (n.).2


    place in eastern Wales, the name is Old English, literally "at the red bank," from Old English read (dative singular readan; from PIE root *reudh- "red, ruddy") + ofer "bank, slope."ETD Radnor.2

    radon (n.)

    the heaviest gaseous element, short-lived and radioactive, 1918, from German Radon, from radium (q.v.) + -on suffix of inert gases. The element was identified in radioactive decay of radium. Alternative name niton (from Latin nitens "shining") gained currency in France and Germany.ETD radon (n.).2

    radula (n.)

    1753, a type of surgical instrument, from Latin radula "scraper, scraping iron," from radere "to scrape" (see raze (v.). As "tongue or lingual ribbon of a mollusk," by 1853. Related: Radular.ETD radula (n.).2

    Larger font
    Smaller font