英语词源字典 - 在线词源网站

clean (v.)[clean 词源字典]: mid-15c., "make clean," from clean (adj.). Related: Cleaned; cleaning. From clean out "clean by emptying" comes sense of "to leave bare" (1844); cleaned-out "left penniless by losses" is from 1812.[clean etymology, clean origin, 英语词源]
clean (adv.): Old English clæne "dirtlessly," also "clearly, fully, entirely;" see clean (adj.). Compare similar use of German rein "clean."
clean-cut (adj.): "precise," 1829 (of turf), from clean (adv.) + past participle of cut (v.).
clean-living (adj.): 1920, from clean (adv.) + live (v.).
clean-up (n.): also cleanup, 1856, "act of cleaning up," from clean + up. Meaning "a profit" is recorded from 1878. Verbal phrase clean up "make a large profit" is from 1929. The adjective, in the baseball sense, is recorded by 1910.
cleaner (n.): mid-15c., agent noun from clean (v.). Meaning "shop that cleans clothes" is from 1873. To take (someone) to the cleaners "get all of (someone's) money" is from 1921.
cleanliness (n.): early 15c., from cleanly + -ness.
Cleanliness is indeed next to godliness. [John Wesley, Sermon "On Dress," c. 1791]
cleanly (adj.): Old English clænlic "morally pure, innocent," from clæne (see clean (adj.)). Of persons, "habitually clean," from c. 1500.
cleanly (adv.): Old English clænlice; see clean (adj.) + -ly (2).
cleanness (n.): Old English clænnes "(moral) cleanness, purity, chastity;" see clean (adj.) + -ness. Meaning "absence of dirt or filth" is late 14c.
cleanse (v.): Old English clænsian "to cleanse, purge, purify, chasten, justify," from West Germanic *klainson, from *klainoz (see clean (adj.)). Despite its modern spelling (16c.), it retains its Middle English pronunciation. Related: Cleansed; cleansing.
cleanser (n.): 1520s, "a purgative;" 1560s, "one who cleans," agent noun from cleanse (v.). Meaning "thing that cleanses" is from late 14c. Old English had clænsere "priest."
cleansing (n.): Old English clænsunge "cleansing, purifying, castigation; chastity, purity," verbal noun from the root of cleanse. As a present participle adjective, attested from c. 1300.
clear (adj.): late 13c., "bright," from Old French cler "clear" (of sight and hearing), "light, bright, shining; sparse" (12c., Modern French clair), from Latin clarus "clear, loud," of sounds; figuratively "manifest, plain, evident," in transferred use, of sights, "bright, distinct;" also "illustrious, famous, glorious" (source of Italian chiaro, Spanish claro), from PIE *kle-ro-, from root *kele- (2) "to shout" (see claim (v.)).

The sense evolution involves an identification of the spreading of sound and the spreading of light (compare English loud, used of colors; German hell "clear, bright, shining," of pitch, "distinct, ringing, high"). Of complexion, from c. 1300; of the weather, from late 14c.; of meanings or explanations, "manifest to the mind, comprehensible," c. 1300. (An Old English word for this was sweotol "distinct, clear, evident.") Sense of "free from encumbrance," apparently nautical, developed c. 1500. Phrase in the clear attested from 1715. Clear-sighted is from 1580s (clear-eyed is from 1529s); clear-headed is from 1709.
clear (v.): late 14c., "to fill with light," from clear (adj.). Of weather, from late 14c. Meaning "make clear in the mind" is mid-15c., as is sense of "to remove what clouds." Meaning "to prove innocent" is from late 15c. Meaning "get rid of" is from 1530s.

Meaning "to free from entanglement" is from 1590s; that of "pass without entanglement" is from 1630s. Meaning "to leap clear over" is first attested 1791. Meaning "get approval for" (a proposal, etc.) is from 1944; meaning "establish as suitable for national security work" is from 1948. Related: Cleared; clearing.

To clear (one's) throat is from 1881; earlier clear (one's) voice (1701). To clear out "depart, leave" (1825), perhaps is from the notion of ships satisfying customs, harbor regulations, etc., then setting sail. To clear up is from 1620s, of weather; 1690s as "make clear to the mind." Clear the decks is what is done on a ship before it moves.
clear (adv.): "quite, entirely, wholly," c. 1300, from clear (adj.).
clearance (n.): 1560s, "action of clearing," from clear (v.) + -ance. Meaning "a clear space" is from 1788. Meaning "approval, permission" (especially to land or take off an aircraft) is from 1944, American English; national security sense recorded from 1948. Clearance sale attested by 1843.
clearing (n.): late 14c., "action of making clear," verbal noun from clear (v.). Meaning "land cleared of wood" is from 1818, American English.
clearing-house (n.): also clearinghouse, 1832, from clearing + house (n.). The original was established 1775 in London by the bankers for the adjustment of their mutual claims for checks and bills; later the word was extended to similar institutions.
clearly (adv.): c. 1300, of vision and speech, from clear (adj.) + -ly (2). Meaning "evidently" is from 1560s; as a parenthetical expression in argument, "it is clear," recorded from 1867.