flaw (n.)
early 14c., "a flake" (of snow), also in Middle English "a spark of fire; a splinter," from Old Norse flaga "stone slab, flake" (see flagstone); sense of "defect, fault" first recorded 1580s, first of character, later (c.1600) of material things; probably via notion of a "fragment" broken off.
flaw (v.)
early 15c. (implied in flawed); see flaw (n.). Related: Flawing.
flawless (n.)
1640s, from flaw + -less. Related: Flawlessly; flawlessness.
flax (n.)
Old English fleax "cloth made with flax, linen," from Proto-Germanic *flakhsan (cognates: Old Frisian flax, Middle Dutch and Dutch vlas, Old Saxon flas, Old High German flahs, German Flachs), probably from Proto-Germanic base *fleh-, corresponding to PIE *plek- "to weave, plait" (see ply (v.1)). But some connect it with PIE *pleik- (see flay) from the notion of "stripping" fiber to prepare it.
flaxen (adj.)
"made of flax," mid-15c., from flax + -en (2). As "the color of flax" (usually with reference to hair) it is attested from 1520s.
flaxseed (n.)
1560s, from flax + seed (n.).
flay (v.)
Old English flean "to skin" (strong verb, past tense flog, past participle flagen), from Proto-Germanic *flahan (cognates: Middle Dutch vlaen, Old High German flahan, Old Norse fla), from PIE root *pl(e)ik-, *pleik- "to tear" (cognates: Lithuanian plešiu "to tear"). Related: Flayed; flaying.
flea (n.)
Old English flea, from Proto-Germanic *flauhaz (cognates: Old Norse flo, Middle Dutch vlo, German Floh), perhaps related to Old English fleon "to flee," with a notion of "the jumping parasite," or perhaps from PIE *plou- "flea" (cognates: Latin pulex, Greek psylla; see puce).

Flea-bag "bed" is from 1839; flea circus is from 1886; flea collar is from 1953.
"A man named 'Mueller' put on the first trained-flea circus in America at the old Stone and Austin museum in Boston nearly forty years ago. Another German named 'Auvershleg' had the first traveling flea circus in this country thirty years ago. In addition to fairs and museums, I get as high as $25 for a private exhibition." ["Professor" William Heckler, quoted in "Popular Mechanics," February 1928. Printed at the top of his programs were "Every action is visible to the naked eye" and "No danger of desertion."]
flea market (n.)
1917, especially in reference to the 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." [E.S. Dougherty, "In Europe," 1922].
fleck (v.)
late 14c., probably from Old Norse flekka "to spot," from Proto-Germanic *flekk- (cognates: Middle Dutch vlecke, Old High German flec, German Fleck), from PIE *pleik- "to tear" (see flay). Related: Flecked; flecking.
fleck (n.)
1590s, from fleck (v.) or else from Middle Dutch vlecke or Old Norse flekkr.
fled
past tense and past participle of flee (q.v.).
fledge (v.)
Old English *-flycge (Kentish -flecge),an adjective meaning "having the feathers, fit to fly," from West Germanic *fluggja- (cognates: Middle Dutch vlugge, Low German flügge), from root meaning "to fly" (see fly (v.)). As a verb, it is first attested in English 1560s. Related: Fledged; fledging.
fledgling
1830 (adj.), 1846 as a noun meaning "young bird," from fledge + diminutive suffix -ling. Of persons, from 1856.
flee (v.)
Old English fleon "take flight, fly from, avoid, escape" (contracted class II strong verb; past tense fleah, past participle flogen), from Proto-Germanic *fleuhan (cognates: Old High German fliohan, Old Norse flöja, Old Frisian flia, Dutch vlieden, German fliehen, Gothic þliuhan "to flee"), possibly from PIE *pleu- "to flow" (see pluvial).

Weak past tense and past participle fled emerged Middle English, under influence of Scandinavian. Old English had a transitive form, geflieman "put to flight," which came in handy in the Anglo-Saxon Chronicle. Related: Fleeing.
fleece (v.)
1530s in the literal sense of "to strip a sheep of fleece;" 1570s in the figurative meaning "to cheat, swindle," from fleece (n.). Related: Fleeced; fleecing.
fleece (n.)
Old English fleos, from West Germanic *flusaz (cognates: Middle Dutch vluus, Dutch vlies, Middle High German vlius, German Vlies), probably from PIE *pleus- "to pluck," also "a feather, fleece" (cognates: Latin pluma "feather, down," Lithuanian plunksna "feather").
fleecy (adj.)
1560s, from fleece (n.) + -y (2).
fleer (v.)
c.1400, perhaps from Scandinavian (compare dialectal Norwegian flira, dialectal Danish flire "to grin, titter"). Related: Fleered; fleering.
fleet (n.)
Old English fleot "ship, raft, floating vessel," from fleotan "to float" (see fleet (v.)). Sense of "naval force" is pre-1200. The Old English 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.
fleet (adj.)
"swift," 1520s, but probably older than the record; apparently from or cognate with Old Norse fliotr "swift," and from the root of fleet (v.)). Related: Fleetness.
fleet (v.)
Old English fleotan "to float, drift, flow, swim, sail," later (c.1200) "to flow," from Proto-Germanic *fleut- (cognates: Old Frisian fliata, Old Saxon fliotan "to flow," Old High German fliozzan "to float, flow," German flieszen "to flow," Old Norse fliota "to float, flow"), from PIE root *pleu- "to flow, run, swim" (see pluvial).

Meaning "to glide away like a stream, vanish imperceptibly" is from c.1200; hence "to fade, to vanish" (1570s). Related: Fleeted; fleeting.
fleeting (adj.)
early 13c., "fickle, shifting, unstable," from Old English fleotende "floating, drifting," later "flying, moving swiftly," from present participle of fleotan (see fleet (v.)). Meaning "existing only briefly" is from 1560s.
Fleming (n.)
Old English Flæming "native or inhabitant of Flanders," and Old Frisian Fleming, from Proto-Germanic *Flam- (source also of Medieval Latin Flamingus); see Flanders.
Flemish (adj.)
early 14c., flemmysshe, probably from Old Frisian Flemische, or from Fleming + -ish.
flense (v.)
also flench, 1814, from Danish flense, perhaps from PIE root *(s)plei- "to splice, split." Related: Flenser; flensing.
flesh (n.)
Old English flæsc "flesh, meat," also "near kindred" (a sense now obsolete except in phrase flesh and blood), common West and North Germanic (compare Old Frisian flesk, Middle Low German vlees, German Fleisch "flesh," Old Norse flesk "pork, bacon"), of uncertain origin, perhaps from Proto-Germanic *flaiskoz-.

Figurative use for "animal or physical nature of man" (Old English) is from the Bible, especially Paul's use of Greek sarx, which yielded sense of "sensual appetites" (c.1200). Flesh-wound is from 1670s; flesh-color, the hue of "Caucasian" skin, is first recorded 1610s, described as a tint composed of "a light pink with a little yellow" [O'Neill, "Dyeing," 1862]. An Old English poetry-word for "body" was flæsc-hama, literally "flesh-home."
flesh (v.)
1520s, "to render (a hunting animal) eager for prey by rewarding it with flesh from a kill," with figurative extensions, from flesh (n.). Meaning "to clothe or embody with flesh," with figurative extensions, is from 1660s. Related: Fleshed; fleshing.
fleshly (adj.)
Old English flæsclic; see flesh (n.) + -ly (1).
fleshpot (n.)
from flesh (n.) + pot (n.1); literally "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]
fleshy (adj.)
"plump," mid-14c., from flesh (n.) + -y (2). Related: Fleshiness.
fletch (v.)
mid-17c., variant of fledge (v.); also see fletcher. Related: Fletched; fletching.
fletcher (n.)
"arrow-maker," early 14c. (as a surname attested from 1203), from Old French flechier, from fleche "arrow," probably from Frankish, from Proto-Germanic *fleug-ika- (compare Old Low German fliuca, Middle Dutch vliecke), from PIE *pleuk-, extended form of root *pleu- "to flow" (see pluvial).
fleur-de-lis (n.)
also fleur de lis, mid-14c., from Old French, literally "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.
fleuret (n.)
"small flower," 1811, from French fleurette, diminutive of fleur (see flower (n.)).
flew
past tense of fly (v.1).
flex (v.)
1520s, probably a back-formation from flexible. Related: Flexed; flexing.
flexibility (n.)
1610s, of physical things, from French flexibilité or directly from Late Latin flexibilitatem (nominative flexibilitas), from Latin flexibilis (see flexible). Of immaterial things from 1783.
flexible (adj.)
early 15c., from Middle French flexible or directly from Latin flexibilis "that may be bent, pliant, flexible, yielding;" figuratively "tractable, inconstant," from flexus, past participle of flectere "to bend," of uncertain origin. Related: Flexibly.
flexion (n.)
c.1600, from Latin flexionem (nominative flexio) "a bending, swaying; bend, turn, curve," noun of action from past participle stem of flectere "to bend" (see flexible).
flexor (n.)
1610s, Modern Latin, short for musculus flexor "a bending muscle," agent noun from past participle stem of Latin flectere "to bend" (see flexible).
flextime (n.)
1972, translating German Gleitzeit "sliding time." See flex + time (n.).
flibbertigibbet (n.)
1540s, "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 c.1600.
flick (n.)
mid-15c., 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 (v.), from their flickering appearance.
flick (v.)
1816, from flick (n.); meaning "quick turn of the wrist" is from 1897, originally in cricket. Related: Flicked; flicking.
flicker (n.)
1849, "wavering, unsteady light or flame;" 1857 as "a flickering," from flicker (v.).
flicker (v.)
Old English flicorian "to flutter, flap quickly and lightly," originally of birds. Onomatopoeic and suggestive of quick motion. Sense of "shine with a wavering light" is c.1600, but not common till 19c. Related: Flickered; flickering.
flicker (n.)
"woodpecker," 1808, American English, possibly echoic of bird's note, or from white spots on plumage that seem to flicker as it flits from tree to tree.
flier (n.)
see flyer.
flight (n.1)
"act of flying," Old English flyht "a flying, flight," from Proto-Germanic *flukhtiz (cognates: Dutch vlucht "flight of birds," Old Norse flugr, Old High German flug, German Flug "flight"), from root of *fleugan "to fly" (see fly (v.1)).

Spelling altered late 14c. from Middle English fliht (see fight (v.)). Meaning "an instance of flight" is 1785, originally of ballooning. Meaning "series of stairs between landings" is from 1703.