A- (3) prefix meaning "not," from Gk a-, an- "not," from pie base *ne "not" (see un-)

flagellation --- 1426, from L. flagellationem (nom. flagellatio) "a scourging," from flagellare, from flagellum "whip," dim. of flagrum "whip, scourge." Flagellate is 1623, from L. flagellatus, pp. of flagellare.

flagitious --- shamefully wicked, vile, scandalous, 1382, from O.Fr. flagicieux, from L. flagitiosus, from flagitium "shameful crime," related to flagrum (see flagrant).

flagon --- 1459, from M.Fr. flacon, from O.Fr. flacon, from L.L. flasconem "bottle" (see flask).

flagrant --- c.1500, "resplendent," from L. flagrantem (nom. flagrans) "burning," prp. of flagrare "to burn," from L. root *flag-, corresponding to PIE *bhleg- (cf. Gk. phlegein "to burn, scorch," O.E. blæc "black"). Sense of "glaringly offensive" first recorded 1706, probably from common legalese phrase in flagrante delicto "red-handed," lit. "with the crime still blazing."

flagstone --- 1730, from flag "flat, split stone" (1604), earlier "piece cut from sod" (1415), from O.N. flaga "stone slab," of unknown origin, perhaps related to O.N. flak (see flake).

Flaherty --- Ir. Flaithbheartach, lit. "Bright-Ruler."

flail (n.) --- implement for threshing grain, c.1100, from an unrecorded O.E. *flegel, which probably represents W.Gmc. *flagil (cf. M.Du., Low Ger. vlegel, O.H.G. flegel, Ger. flegel), a borrowing of L.L. flagellum "winnowing tool, flail," from L. flagellum "whip." The v. is 15c., from the n.; originally "to scourge;" sense of "to move like a flail" is from 1874.

flair --- c.1340, "an odor," from O.Fr. flair "odor or scent," from flairer "to smell," from L.L. fragrare "emit (a sweet) odor" (see fragrant), with shift of -r- to -l- by dissimilation. Sense of "special aptitude" is Amer.Eng. 1925, perhaps from notion of a hound's ability to track scent.

flak --- 1938, from Ger. Flak, acronym for Fliegerabwehrkanone "airplane defense cannon." Sense of "anti-aircraft fire" is 1940; metaphoric sense of "criticism" is c.1963 in Amer.Eng.

flake (n.) --- c.1330, possibly from O.E. *flacca "flakes of snow," from O.N. flak "loose or torn piece" (related to O.N. fla "to skin," see flay), from P.Gmc. *flak- (cf. M.Du. vlac "flat, level," M.H.G. vlach, Ger. Flocke "flake"); from the same PIE root as L. plaga "a flat surface, district, region." Flaky "eccentric, crazy" first recorded 1959, said to be Amer.Eng. baseball slang, but probably from earlier druggie slang flake "cocaine" (1920s). Flake "eccentric person" is a 1968 back-formation from flaky. "The term 'flake' needs explanation. It's an insider's word, used throughout baseball, usually as an adjective; someone is considered 'flaky.' It does not mean anything so crude as 'crazy,' but it's well beyond 'screwball' and far off to the side of 'eccentric.' " ["New York Times," April 26, 1964]

flambé --- 1886, of certain types of porcelain, 1906 as a term in cookery, from Fr., pp. of flamber "to singe, blaze," from O.Fr. flambe "flame."

flamboyant --- 1832, first used of a 15c.-16c. architectural style with flame-like curves, from Fr. flamboyant "flaming, wavy," prp. of flamboyer "to flame," from O.Fr. flamboier, from flambe "flame." Extended sense of "showy, ornate" is 1879.

flame (n.) --- c.1340, from Anglo-Fr. flaume, from O.Fr. flamme, from L. flammula "small flame," dim. of flamma "flame," from PIE *bhleg-/*phleg-. The meaning "a sweetheart" is attested from 1647; the fig sense of "burning passion" was in M.E. The verb is M.E. flamen, from O.Fr. flamer; the verb sense of "unleash invective on a computer network" is from 1980s. Flamer, flaming "glaringly homosexual" are homosexual slang from 1970s, but flamer "glaringly conspicuous person or thing" (1809) and flaming "glaringly conspicuous" (1781) are much earlier in the general sense, both originally with reference to "wenches." Flaming as an intensifying adj. dates from late 19c. Flame-thrower (1917) translates Ger. flammenwerfer (1915).

flamen --- ancient Roman priest, 1533, from L. flamen, of unknown origin, perhaps from the same PIE root as Goth. blotan, O.E. blotan "to sacrifice." Also used from c.1330 in reference to the ancient pre-Christian British priests, in imitation of Geoffrey of Monmouth.

flamenco --- 1896, from Sp. flamenco, first used of Gypsy dancing in Andalusia. The word means "Fleming, native of Flanders" (Du. Vlaming) and also "flamingo." Speculation are varied and colorful about the connection between the bird, the people, and the gypsy dance of Andalusia. Spain ruled Flanders for many years, and King Carlos I brought with him to Madrid an entire Flemish court. One etymology suggests the dance was so called from the bright costumes and energetic movements, which the Sp. associated with Flanders; another is that Spaniards, especially Andalusians, like to name things by their opposites, and since the Flemish were tall and blond and the gypsies short and dark, the gypsies were called "Flemish;" others hold that flamenco was the general Sp. word for all foreigners, gypsies included; or that Flemish noblemen, bored with court life, took to partying with the gypsies.

flamingo --- 1565, from Port. flamengo, Sp. flamengo, lit. "flame-colored" (cf Gk. phoinikopteros "flamingo," lit. "red-feathered"), from Prov. flamenc, from flama "flame" + Gmc. suffix -enc "-ing, belonging to."

flammable --- 1813, from L. flammare "to set on fire" + -able.

flan --- open tart, 1846, from Fr. flan "custard tart, cheesecake," from O.Fr. flaon, from M.L. flado, a Gmc. borrowing, from P.Gmc. *fladu- (cf. Frank. *flado, O.H.G. flado "offering cake," M.H.G. vlade "a broad, thin cake," Du. vla "baked custard"), akin to words for flat (q.v.), probably from PIE base *pele- "spread out, broad, flat" (see plane (1)).

flâneur --- loafer, idler, 1854, from Fr. flâner "to stroll, loaf, saunter," probably from a Scand. source (cf. Norw. flana, flanta "to gad about").

flange --- 1688, perhaps related to O.Fr. flanche "flank, side," fem. of flanc (see flank).

flank (n.) --- late O.E. flanc "fleshy part of the side," from O.Fr. flanc, probably from Frank. *hlanca (cf. O.H.G. (h)lanca, M.H.G. lanke "hip joint," Ger. lenken "to bend, turn, lead"), from PIE base *qleng- "to bend." The military sense is first attested 1548, as is the verb.

flannel --- 1503, from Welsh gwlanen "woolen cloth," from gwlan "wool." Not a universally accepted etymology; some suggest an Anglo-Fr. dim. of O.Fr. flaine "a kind of coarse wool."

flap (n.) --- c.1320, flappe "a blow, slap," probably imitative of the sound of striking. Meaning "something that hangs down" is first recorded 1522; the verb meaning "to swing loosely" is from 1529. Sense of "motion or noise like a bird's wing" is 1774; meaning "disturbance, noisy tumult" is 1916, British slang. Flapjack is pre-1600, using the personal name.

flapdoodle --- 1833, originally "the stuff they feed fools on" [Marryat]; an arbitrary formation.

flapper --- forward young woman, 1921 slang, from flap (v.), but the exact connection is disputed. Perhaps from flapper "young wild-duck or partridge" (1747), with ref. to flapping wings while learning to fly; but other suggested sources are late 19c. northern Eng. dialectal use for "teen-age girl" (on notion of one with the hair not yet put up), or an earlier meaning "prostitute" (1889), which is perhaps from dial. flap "young woman of loose character" (1613). In Britain the word took on political tones in ref. to the debate over voting rights. " 'Flapper' is the popular press catch-word for an adult woman worker, aged twenty-one to thirty, when it is a question of giving her the vote under the same conditions as men of the same age." ["Punch," Nov. 30, 1927]

flare (v.) --- c.1550, originally "spread out" (hair), of unknown origin, perhaps from Du. vlederen. The noun meaning "bright, unsteady light" is 1814, from the verb, which led to the sense of "signal fire" (1883). The notion of "spreading out in display" is behind the notion of "spreading gradually outward" (1644). Flare-up "a sudden burst" is from 1837. Flares "flared trousers" is from 1964.

flash --- 1387, from flasken (c.1300) "to dash or splash" (as water), probably imitative. Sense of "sudden burst of light or flame" is 1548, as is the noun. Meaning "photographic lamp" is from 1913. Flashy "showy, cheaply attractive" is first recorded 1690. Flashlight, Amer.Eng. for "electric torch," is from 1919. Flashback is 1916 as a plot device in novels or movies; 1960s as a type of hallucination. Flasher "male genital exhibitionist" is 1960s, though meat-flasher in this sense was attested in 1890s. Flash in the pan (1809) is from old-style guns, where the powder might ignite in the pan but fail to spark the main charge.

flask --- 1355, from M.L. flasco "container, bottle," from L.L. flasconem "bottle," probably from a Gmc. source (cf. O.E. flasce, O.H.G. flaska, M.Du. flasce, Ger. Flasche "bottle"), probably originally meaning "a bottle plaited round, case bottle" (cf. O.H.G. flechtan "to weave," O.E. fleohtan "to braid, plait"), from P.Gmc. base *fleh- (see flax). Another theory traces it to a metathesis of L. vasculum.

flat (adj.) --- c.1320, from O.N. flatr, from P.Gmc. *flataz (cf. O.H.G. flaz "flat, level," O.E. flet, O.H.G. flezzi "floor"), perhaps from PIE *pla- (cf. Gk. platys "broad, flat;" see place (n.)). Sense of "prosaic, dull" is from 1573; used of drink from 1607; of musical notes from 1591, because the tone is "lowered." Flatfish is from 1710. Flat-footed "unprepared" is 1912 U.S. baseball slang, on notion of "not on one's toes; earlier it meant "straightforwardly" (1828), from notion of "standing firmly." Flat-out (adv.) "openly, directly" is from 1932; earlier it was a noun meaning "total failure" (1870, U.S. colloquial). Flatware is distinguished from hollow ware.

flat (n.) --- 1801, from Scot. flat "floor or story of a house," from O.E. flet "a dwelling, floor, ground," from the same source as flat (adj.).

flatter --- c.1225, from O.Fr. flater "to flatter," originally "stroke with the hand, caress," from Frank. *flat "palm, flat of the hand" (see flat (adj.)).

flatulent --- 1599, from M.Fr. flatulent, from L. flatus "a blowing, a breaking wind," pp. of flare "to blow, puff," which is cognate with O.E. blawan (see blow (v.1)).

flaunt --- 1566, "to display oneself in flashy clothes," of unknown origin; perhaps a variant of flout or vaunt. It looks Fr., but it corresponds to no known Fr. word. Transitive sense is from 1827.

flautist --- 1860, from It. flautista, from flauto "flute" (from L. flauta, see flute) + Gk.-derived suffix -ista.

Flavius --- male proper name, from L. Flavius, a Roman gens name, related to flavus "yellow" (see blue), and probably originally meaning "yellow-haired."

flavor --- c.1300, "a smell, odor," from O.Fr. flaour "smell, odor," from V.L. flator "odor," lit. "that which blows," from L. flator "blower," from flare "to blow, puff," which is cognate with O.E. blawan (see blow (v.1)). The same V.L. source produced O.It. fiatore "a bad odor." Sense of "taste, savor" is 1697, originally "the element in taste which depends on the sense of smell." The -v- is perhaps from infl. of savor.

flaw --- c.1325, "snowflake, spark of fire," from O.N. flaga "stone slab, flake" (see flagstone); sense of "defect, fault" first recorded 1586, first of character, later (1604) of material things; probably via notion of a "fragment" broken off.

flax --- O.E. fleax "cloth made with flax, linen," from P.Gmc. *flakhsan (cf. O.Fris. flax, Ger. Flachs), probably from P.Gmc. base *fleh-, corresponding to PIE *plek- "to weave, plait" see ply (v.)). But some connect it with PIE *plak- (see flay) from the notion of "stripping" fiber to prepare it. Flaxen "made of flax" is from O.E. fleaxen; as "the color of flax" (usually with reference to hair) it is attested from 1523.

flay --- O.E. flean "to skin" (strong verb, pt. flog, pp. flagen), from P.Gmc. *flakhanan (cf. M.Du. vlaen, O.N. fla), from PIE root *plak- (cf. Gk. plessein "to strike").

flea --- O.E. fleah, from P.Gmc. *flaukh- (cf. O.N. flo, M.Du. vlo, Ger. floh), perhaps related to O.E. fleon "to flee," with a notion of "the jumping parasite." Flea market (1920), especially the Fr. marché aux puces in Paris, so-called "because there are so many second-hand articles sold of all kinds that they are believed to gather fleas."

fleck (v.) --- c.1430, from O.N. flekka "to spot," from P.Gmc. *flekk- (cf. M.Du. vlecke, O.H.G. flec, Ger. Fleck). The noun is first recorded 1598, probably from the verb.

fledge --- O.E. flycge (Kentish fligge), from W.Gmc. *fluggja- (cf. M.Du. vlugge, Low Ger. flügge). Originally an adj. meaning "having the feathers, fit to fly." As a verb, it is first attested in Eng. 1566. Fledgling is first recorded 1830.

flee --- O.E. fleon "take flight" (contracted class II strong verb; past tense fleah, pp. flogen), from P.Gmc. *thleukhanan (cf. O.H.G. fliohan, O.N. flöja, Du. vlieden, Ger. fliehen, Goth. þliuhan "to flee"), of unknown origin. Not found outside Gmc. Weak pt./pp. fled emerged M.E., under influence of Scand. O.E. had a trans. form, geflieman "put to flight," which came in handy in the Anglo-Saxon Chronicle.

fleece (n.) --- O.E. fleos, from W.Gmc. *flusaz (cf. M.Du. vluus, M.H.G. vlius, Ger. Vlies), probably from PIE *plus- (cf. L. pluma "feather, down," Lith. plunksna "feather"). The verb is 1537 in the literal sense of "to strip a sheep of fleece" and 1577 in the fig. meaning "to cheat, swindle."

fleer (v.) --- c.1400, perhaps from Scand. (cf. dial. Norw. flira, dial. Dan. flire "to grin, titter").

fleet (n.) --- O.E. fleot "ship, floating vessel," from fleotan "to float," from P.Gmc. *fleut-, from PIE base *pleu- "to flow, run, swim." Sense of "naval force" is pre-1200. The O.E. word also meant "creek, inlet, flow of water," especially one into the Thames near Ludgate Hill, which lent its name to Fleet Street (home of newspaper and magazine houses, standing for "the English press" since 1882), Fleet prison, etc.

fleeting (adj.) --- c.1225, from O.E. fleotende "floating, drifting," later "flying, moving swiftly," from O.E. fleotan (see fleet (n.)).

Fleming --- O.E. Flæming "native or inhabitant of Flanders," from P.Gmc. *Flam- (cf. M.L. Flamingus).

flesh --- O.E. flæsc "flesh, meat," also "near kindred" (a sense now obsolete except in phrase flesh and blood), common W. and N.Gmc. (cf. O.Fris. flesk, M.L.G. vlees, Ger. Fleisch "flesh," O.N. flesk "pork, bacon"), of unknown origin, perhaps from P.Gmc. *flaiskoz-. Figurative use for "animal or physical nature of man" (O.E.), is from the Bible, especially Paul's use of Gk. sarx, which yielded sense of "sensual appetites" (c.1200). Fleshpot is lit. "pot in which flesh is boiled," hence "luxuries regarded with envy," especially in fleshpots of Egypt, from Exodus xvi.3: "Whan we sat by ye Flesh pottes, and had bred ynough to eate." [Coverdale translation, 1535] Flesh-wound is from 1674; flesh-color, the hue of "Caucasian" skin, is first recorded 1611, described as a tint composed of "a light pink with a little yellow" [O'Neill, "Dyeing," 1862]. Fleshy "plump" is from c.1369. An O.E. poetry-word for "body" was flæsc-hama, lit. "flesh-home."

fletcher --- arrow-maker, c.1330 (as a surname attested from 1203), from O.Fr. flechier, from fleche "arrow," probably from Frank. *fliugica (cf. O.Low Ger. fliuca, M.Du. vliecke).

fleur-de-lis --- 1352, from O.Fr., lit. "flower of the lily," especially borne as a heraldic device on the royal arms of France. Perhaps originally representing an iris, or the head of a scepter, or a weapon of some sort.

flexible --- c.1412, from L. flexibilis "that may be bent, pliant," from flexus, pp. of flectere "to bend," of uncertain origin. Flex is a back-formation, first recorded 1521.

flibbertigibbet --- 1549, "chattering gossip, flighty woman," probably a nonsense word meant to sound like fast talking; as the name of a devil or fiend it dates from 1603.

flick (n.) --- c.1447, probably imitative of a light blow with a whip. Earliest recorded use is in phrase not worth a flykke "useless." As slang for "film," it is first attested 1926, a back-formation from flicker, from their flickering appearance. The verb is first recorded 1838; meaning "quick turn of the wrist" is from 1897, originally in cricket.

flicker (n.) --- woodpecker, 1808 Amer.Eng., possibly echoic of bird's note, or from white spots on plumage that seem to flicker as it flits from tree to tree.

flicker (v.) --- O.E. flicorian "to flutter, flap quickly and lightly," originally of birds. Onomatopoeic of quick motion. Sense of "shine with a wavering light" is 1605, but not common till 19c.

flight (1) --- flying, O.E. flyht "a flying, flight." from P.Gmc. *flukhtiz (cf. Low Ger. flugt, Ger. Flucht). Spelling altered from M.E. fliht c. 1385 (see fight), from root of *fleugan "to fly" (see fly (v.1)). Meaning "an instance of flight" is 1785, originally of ballooning. Meaning "series of stairs between landings" is from 1703. Flighty is 1552 in sense of "swift," later (1768) "fickle or frivolous," originally of skittish horses.

flight (2) --- fleeing, from M.E. fluht (c.1200), not found in O.E., but presumed to have existed. Related to O.E. fleon "flee" (see flee).

flim-flam --- 1538 (n.); 1660 (v.); a contemptuous echoic construction, perhaps connected to some unrecorded dial. word from Scandinavian (cf. O.N. flim "a lampoon").

flimsy --- 1702, perhaps a metathesis of film "gauzy covering."

flinch --- 1579, from obsolete flecche "to bend, flinch," probably from O.Fr. flenchir "to bend," from Frank. *hlankjan (cf. M.H.G. linken, Ger. lenken "to bend, turn, lead").

flinders --- 1450, Scottish flendris, probably related to Norw. flindra "chip, splinter," or Du. flenter "fragment," ult. from the same PIE root that produced flint (q.v.).

fling (v.) --- c.1300, probably from O.N. flengja, of uncertain origin. The M.E. intransitive sense is preserved in phrase have a fling at "make a try." The noun sense of "period of indulgence on the eve of responsibilities" first attested 1827. Meaning "vigorous dance" (associated with the Scottish Highlands) is from 1806. An obsolete word for "streetwalker, harlot" was fling-stink (1679).

flint --- O.E. flint "flint, rock," common Gmc. (cf. M.Du. vlint, O.H.G. flins, Dan. flint), from PIE *splind- "to split, cleave," from base *(s)plei- "to splice, split" (cf. Gk. plinthos "brick, tile," O.Ir. slind "brick"). Transferred senses were in O.E. Flintlock as a type of musket-firing mechanism is from 1683. Flinty "hard-hearted" is from 1536.

flip (n.) --- sailors' hot drink usually containing beer, brandy and sugar, 1695, from flip (v.), so called from notion of it being "whipped up" or beaten.

flip (v.) --- 1594, possibly imitative; or a contraction of fillip (q.v.), which also is held to be imitative. Sense of "get excited" is first recorded 1950; flip one's lid "lose one's head, go wild" is from 1951. For flip (adj.) "glib," see flippant. Flipping (adj.) as euphemism for fucking is British slang first recorded 1911 in D.H. Lawrence.

flip-flop --- thong sandal, 1960s, imitative of the sound of walking in them (flip-flap had been used in various echoic senses since 1529); sense of "complete reversal of direction" dates from 1900.

flippant --- displaying unbecoming levity, 1605, apparently an extended form of flip (v.) (q.v.). Shortened form flip is attested from 1847.

flipper --- limb used to swim with, 1822, from the verb. Sense of "rubber fin for underwater swimming" is from 1945. Slang meaning "the hand" dates from 1836.

flirt (v.) --- 1553, originally "to turn up one's nose, sneer at," then "to rap or flick, as with the fingers" (1563). The noun is first attested 1549, with the meaning "stroke of wit." It's possible that the original word was imitative, along the lines of flip (v.), but there seems to be some influence from flit, such as in the flirt sense of "to move in short, quick flights," attested from 1583. Meanwhile flirt had come to mean "a pert young hussey" [Johnson] by 1562, and Shakespeare has flirt-gill (i.e. Jill) "a woman of light or loose behavior," while flirtgig was a 17c. Yorkshire dialect word for "a giddy, flighty girl." All or any of these could have fed into the main modern verbal sense of "play at courtship" (1777), which also could have grown naturally from the earlier meaning "to flit inconstantly from object to object" (1578), perhaps influenced by O.Fr. fleureter "talk sweet nonsense," also "to touch a thing in passing," dim. of fleur "flower" and metaphoric of bees skimming from flower to flower. The noun meaning "person who flirts" is from 1732. The Eng. word also is possibly related to E.Fris. flirt "a flick or light blow," and flirtje "a giddy girl."

flit --- c.1200, flutten "convey, move, take," perhaps from O.N. flytja "cause to fit," from P.Gmc. *flotojan (see float). First record of flitter, with frequentative suffix, is from 1542. Flitter-mouse (1547) is occasionally used in Eng., in imitation of Ger. fledermaus "bat," from O.H.G. fledaron "to flutter." "Theire desire ... is to goe to theire newe masters eyther on a Tewsday, or on a Thursday; for ... they say Munday flitte, Neaver sitte." [1641]

flitch --- side of bacon, M.E. flicche, from O.E. flicce, related to O.N. flikki, M.L.G. vlicke "piece of flesh." Not connected to flesh. A flitch was presented every year at Dunmow, in Essex, to any married couple who could prove they had lived together without quarreling for a year and a day, a custom mentioned as far back as 1362.

flivver --- cheap car, especially "Model-T Ford," 1910, of unknown origin.

float --- O.E. flotian "to float" (class II strong verb; past tense fleat, pp. floten), from P.Gmc. *flutojanan (cf. O.N. flota, M.Du. vloten). The noun meaning "platform on wheels used for displays in parades, etc." is from 1888, probably from earlier sense of "flat-bottomed boat" (1557). Floater "dead body found in water" is 1890, U.S. slang.

floccinaucinihilipilification --- action or habit of estimating as worthless, 1741, a combination of four Latin words (flocci, nauci, nihili, pilifi) all signifying "at a small price" or "for nothing," which were listed together in a rule of the well-known Eton Latin Grammar. The kind of jocular formation that was possible among educated men in Britain in those days. Just so, as in praesenti, the opening words of mnemonic lines on conjugation in Lilley's 16c. Latin grammar, could stand alone as late as 19c. and be understood to mean "rudiments of Latin."

flock (n.) --- O.E. flocc "a group of persons," related to O.N. flokkr "crowd, troop, band," M.L.G. vlocke "crowd, flock;" not found in other Gmc. languages, perhaps related to folc "people," but the metathesis would have been unusual for O.E. Extended c.1200 to "a number of animals of one kind moving or feeding together;" of domestic animals c.1300. Transferred to bodies of Christians, in relation to Christ or their local pastor, from c.1340. The verb meaning "to gather, congregate" is from c.1300.

floe --- 1817, first used by Arctic explorers, probably from Norw. flo "layer, slab," from O.N. flo, related to first element in flagstone (q.v.). Earlier explorers used flake.

flog --- 1676, slang, perhaps a schoolboy shortening of L. flagellare "flagellate."

flood (n.) --- O.E. flod "a flowing of water, river, sea, flood," from P.Gmc. *flothuz (cf. O.Fris. flod, O.N. floð, M.Du. vloet, Ger. Flut, Goth. fiodus), from PIE verbal stem *plo-/*pleu- "flow, float" (cf. Gk. ploein "to float, swim," plotos "floating, navigable"). The verb is first attested 1663. Floodgate (c.1225) is earlier recorded in the fig. sense (especially with reference to tears or rain) than in the literal sense (1440).

floor (n.) --- O.E. flor "floor," from P.Gmc. *floruz "floor" (cf. M.Du. vloer, O.N. flor "floor," M.H.G. vluor, Ger. Flur "field, meadow"), from PIE *plaros (cf. Welsh llawr "ground"), enlarged from *pele- "flat, to spread." The verbal sense of "puzzle, confound" is 1830, from notion of "knock down to the floor" (1642). The fig. sense in legislative assemblies is first recorded 1774.