英语词源字典 - 在线词源网站

redline (v.)[redline 词源字典]: also red-line, "mark in red ink," 1820, from red (adj.1) + line (v.). Specific sense of "deny loans to certain neighborhoods based on ethnicity" is from 1973, on notion of lines drawn on maps. Used earlier in reference to insurance company practices (1961) and in World War II military slang in reference to a red line drawn through a soldier's name for some infraction, thus denying his pay. Related: Redlined; redlining.[redline etymology, redline origin, 英语词源]
redneck (n.): "cracker," attested 1830 in a specialized sense ("This may be ascribed to the Red Necks, a name bestowed upon the Presbyterians in Fayetteville" -- Ann Royall, "Southern Tour I," p.148), from red (adj.1) + neck (n.). According to various theories, red perhaps from anger, or from pellagra, but most likely from mule farmers' outdoors labor in the sun, wearing a shirt and straw hat, with the neck exposed. Compare redshanks, old derogatory name for Scots Highlanders and Celtic Irish (1540s), from their going bare-legged.

It turns up again in an American context in 1904, again from Fayetteville, in a list of dialect words, meaning this time "an uncouth countryman" ["Dialect Notes," American Dialect Society, Vol. II, Part VI, 1904], but seems not to have been in widespread use in the U.S. before c. 1915. In the meantime, it was used from c. 1894 in South Africa (translating Dutch Roinek) as an insulting Boer name for "an Englishman."
Another common Boer name for an Englishman is "redneck," drawn from the fact that the back of an Englishman's neck is often burnt red by the sun. This does not happen to the Boer, who always wears a broad-brimmed hat. [James Bryce, "Impressions of South Africa," London, 1899]
redness (n.): Old English readnes; see from red (adj.1) + -ness.
redo (v.): also re-do, 1590s, from re- "back, again" + do (v.). Related: Redone; redoing.
redolence (n.): early 15c., from Old French redolence, related to redolent (see redolent).
redolent (adj.): c. 1400, from Old French redolent "emitting an odor" and directly from Latin redolentem (moninative redolens), present participle of redolere "emit a scent, diffuse odor," from red-, intensive prefix (see re-), + olere "give off a smell" (see odor).
redouble (v.): mid-15c., "double again, multiply" (trans.), from Middle French redoubler, from Old French re- "again" (see re-) + doubler "to double" (see double (v.)). Meaning "become twice as much" (intrans.) is from late 15c. Related: Redoubled; redoubling.
redoubt (n.): also redout, "small, enclosed military work," c. 1600, from French redoute (17c.), from Italian ridotto, earlier ridotta, "place of retreat," from Medieval Latin reductus "place of refuge, retreat," noun use of past participle of reducere "to lead or bring back" (see reduce). The -b- was added by influence of unrelated English redoubt (v.) "to dread, fear" (see redoubtable). As an adjective, Latin reductus meant "withdrawn, retired; remote, distant."
redoubtable (adj.): late 14c., from Old French redoutable (12c.), from redouter "to dread," from re-, intensive prefix, + douter "be afraid of" (see doubt (v.)).
redound (v.): late 14c., "to overflow," from Old French redonder "overflow, abound, be in profusion" (12c.), from Latin redundare "to overflow" (see redundant). Meaning "to flow or go back" (to a place or person) is from late 14c.; hence "to rebound" (c. 1500), and "to contribute to" (the credit, honor, etc.), early 15c. Related: Redounded; redounding.
redox (n.): 1928, from red(uction) + ox(idation).
redress (v.): mid-14c., "to correct, reform;" late 14c., "restore, put right" (a wrong, error, offense); "repair; relieve; improve; amend," from Old French redrecier "reform, restore, rebuild" (Modern French redresser), from re- "again" (see re-) + drecier "to straighten, arrange" (see dress (v.)). Formerly used in many more senses than currently. Related: Redressed; redressing.
redressal (n.): "a setting right again," 1800, from redress + -al (2). An earlier noun was simply redress "reparation, compensation, adjustment" (late 14c.), from Anglo-French redresce, Old French redrece, redresse
redshirt (v.): "to withdraw (a player) from the varsity team to add a year to his or her eligibility," 1955, in reference to the red shirts worn by athletes on the scrimmage squad; from red (adj.1) + shirt (n.).
redskin (n.): "American Indian," 1690s, from red (adj.1) + skin (n.). Red as the skin color of Native Americans is from 1580s; red man is from 1580s. Also see red cent.
redstart (n.): type of bird, 1560s, from red (adj.1) + start "tail," from Old English steort. Similar formation in German Rotsterz.
redtail (n.): 1812 in reference to a type of North American hawk; earlier used of various smaller European birds with red tail feathers (1550s); from red (adj.1) + tail (n.).
reduce (v.): late 14c., "bring back," from Old French reducer (14c.), from Latin reducere "lead back, bring back," figuratively "restore, replace," from re- "back" (see re-) + ducere "bring, lead" (see duke (n.)). Meaning "bring to an inferior condition" is 1570s; that of "bring to a lower rank" is 1640s (military reduce to ranks is from 1802); that of "subdue by force of arms" is 1610s. Sense of "to lower, diminish, lessen" is from 1787. Related: Reduced; reducing.
reducible (adj.): mid-15c.; see reduce + -ible. Compare Old French redusible.
reductio ad absurdum: Latin, literally "reduction to the absurd." Absurdum is neuter of absurdus. See reduction + absurd. The tactic is useful and unobjectionable in proofs in geometry.