fly (v.2) Look up fly at Dictionary.com
"run away," Old English fleon (see flee). Fleogan and fleon were often confused in Old English, too. Modern English distinguishes in preterite: flew/fled.
fly (adj.) Look up fly at Dictionary.com
slang, "clever, alert, wide awake," late 18c., perhaps from fly (n.) on the notion of the insect being hard to catch. Other theories, however, trace it to fledge or flash. Slang use in 1990s might be a revival or a reinvention.
fly-by-night (n.) Look up fly-by-night at Dictionary.com
1796, slang, said to be an old term of reproach to a woman signifying that she was a witch; extended 1823 to "anyone who departs hastily from a recent activity," especially while owing money. The two senses involve the two verbs fly.
fly-over (n.) Look up fly-over at Dictionary.com
also flyover, 1901 of bridges, 1931, of aircraft flights, from fly (v.1) + over (adv.).
flyer (n.) Look up flyer at Dictionary.com
also flier, mid-15c., "something that flies," agent noun of fly (v.1). Meaning "something that goes fast" is from 1795; that of "aviator" is from 1934. Meaning "speculative investment" is from 1846 (on the notion of a "flying leap"). Meaning "small handbill or fly-sheet" is from 1889, U.S. slang (originally especially of police bulletins), on notion of "made to be scattered broadcast." Meaning "aviator" is from World War I. Related: Fliers; flyers.
flying (adj.) Look up flying at Dictionary.com
Old English fleogende "flying, winged," present participle of fly (v.1). Flying buttress is from 1660s; flying fish is from 1510s. Flying saucer first attested 1947, though the image of saucers for unidentified flying objects is from at least 1880s. Flying Dutchman, ghost ship off the Cape of Good Hope, attested since 1803 [John Leyden, "Scenes of Infancy," who describes it as "a common superstition of mariners"]. Flying colors (1706) probably is from the image of a naval vessel with the national flag bravely displayed.
Flynn Look up Flynn at Dictionary.com
surname, from Irish flann "red."
flypaper (n.) Look up flypaper at Dictionary.com
1851 (though the item itself is said to have become commonly available in London in 1848), from fly (n.1) + paper (n.).
flyte (v.) Look up flyte at Dictionary.com
Old English flitan "to contend, struggle, quarrel;" related to German fleiß, Dutch vlijt "diligence, industry."
flyway (n.) Look up flyway at Dictionary.com
1891, originally of bird migration paths, from fly (v.1) + way (n.).
flywheel (n.) Look up flywheel at Dictionary.com
1784, from fly (n.) "speed-regulating device" (from fly (v.1)) + wheel (n.).
fo'c'sle (n.) Look up fo'c'sle at Dictionary.com
see forecastle.
foal (n.) Look up foal at Dictionary.com
Old English fola "foal, colt," from Proto-Germanic *fulon (cognates: Old Saxon folo, Middle Dutch and Dutch veulen, Old Norse foli, Old Frisian fola, Old High German folo, German Fohlen, Gothic fula), from PIE *pulo- "young of an animal" (cognates: Greek polos "foal," Latin pullus "a young animal," Albanian pele "mare"), from root *pau- "few, little" (see few).
foal (v.) Look up foal at Dictionary.com
"give birth (to a foal)," late 14c., from foal (n.). Related: Foaled; foaling.
foam (n.) Look up foam at Dictionary.com
Old English fam "foam, saliva froth," from West Germanic *faimo- (cognates: Old High German veim, German Feim), from PIE *(s)poi-mo-, a root with connotations of "foam, froth" (cognates: Sanskrit phenah; Latin pumex "pumice," spuma "foam;" Old Church Slavonic pena "foam;" Lithuanian spaine "a streak of foam"). The rubber or plastic variety so called from 1937.
foam (v.) Look up foam at Dictionary.com
Old English famgian "to foam," from the source of foam (n.). Related: Foamed; foaming.
foamy (adj.) Look up foamy at Dictionary.com
Old English faemig; see foam (n.) + -y (2). Related: Foaminess.
fob (n.) Look up fob at Dictionary.com
1650s, "small pocket for valuables," probably related to Low German fobke "pocket," High German fuppe "pocket," "a dialectal word used in Livonia" [Klein]. Meaning "chain attached to a watch carried in the fob" is from 1885.
fob (v.) Look up fob at Dictionary.com
"to cheat," late 14c., from obsolete noun fobbe "cheat, trickster" (late 14c.), perhaps from Old French forbe "cheat" [OED]. Alternative etymology holds that the word is perhaps related to German foppen "to jeer at, make a fool of" (see fop); or from German fuppen, einfuppen "to pocket stealthily," which would connect it to fob (n.). To fob (someone) off is first recorded 1590s. Related: Fobbed; fobbing.
focal (adj.) Look up focal at Dictionary.com
1690s, from Modern Latin focalis; see focus (n.) + -al (1).
foci (n.) Look up foci at Dictionary.com
plural of focus (n.).
focus (n.) Look up focus at Dictionary.com
1640s, from Latin focus "hearth, fireplace" (also, figuratively, "home, family"), of unknown origin, used in post-classical times for "fire" itself, taken by Kepler (1604) in a mathematical sense for "point of convergence," perhaps on analogy of the burning point of a lens (the purely optical sense of the word may have existed before Kepler, but it is not recorded). Introduced into English 1650s by Hobbes. Sense transfer to "center of activity or energy" is first recorded 1796.
focus (v.) Look up focus at Dictionary.com
1775 in the literal sense; 1807 in the figurative sense, from focus (n.). Related: Focused; focusing; less commonly focussed; focussing.
fodder (n.) Look up fodder at Dictionary.com
Old English fodder "food," especially "food for cattle," from Proto-Germanic *fodran (cognates: Old Norse foðr, Middle Dutch voeder, Old High German fuotar, German Futter), from PIE *patrom, from *pa- "to feed" (see food).
foe (n.) Look up foe at Dictionary.com
Old English gefa "foe, enemy, adversary in a blood feud" (the prefix denotes "mutuality"), from fah "at feud, hostile," from Proto-Germanic *fakhaz (cognates: Old High German fehan "to hate," Gothic faih "deception"), probably from PIE root *peig- (2) "evil-minded, treacherous, hostile" (cognates: Sanskrit pisunah "malicious," picacah "demon;" Greek pikros "bitter;" Latin piget "it irks, troubles, displeases," piger "reluctant, lazy;" Lithuanian piktas "wicked, angry," pekti "to blame"). Weaker sense of "adversary" is first recorded c.1600.
foetal (adj.) Look up foetal at Dictionary.com
see fetal; for spelling, see oe.
foetid (adj.) Look up foetid at Dictionary.com
see fetid; for spelling, see oe.
foetus (n.) Look up foetus at Dictionary.com
see fetus; for spelling, see oe.
fog (v.) Look up fog at Dictionary.com
1590s, from fog (n.1). Related: Fogged; fogging.
fog (n.1) Look up fog at Dictionary.com
"thick, obscuring mist," 1540s, probably from a Scandinavian source akin to Danish fog "spray, shower, snowdrift," Old Norse fok "snow flurry," fjuk "snow storm." Compare also Old English fuht, Dutch vocht, German Feucht "moist." Figurative phrase in a fog "at a loss what to do" first recorded c.1600.
fog (n.2) Look up fog at Dictionary.com
"long grass," c.1300, probably of Scandinavian origin; compare Norwegian fogg "long grass in a moist hollow," Icelandic fuki "rotten sea grass." The connection to fog (n.1), via a notion of long grass growing in moist dells of northern Europe, is tempting but not proven. Watkins suggests derivation from PIE *pu- "to rot, decay."
Fogarty Look up Fogarty at Dictionary.com
surname, from Old Irish fogartach "banished."
fogey (n.) Look up fogey at Dictionary.com
also fogy, "an old, dull fellow," 1780, Scottish foggie, originally "army pensioner or veteran," perhaps connected to fogram (1775) "old-fashioned person;" or from fog in obsolete senses of "moss" or "bloated fat" (1580s).
foggy (adj.) Look up foggy at Dictionary.com
1540s, perhaps from a Scandinavian source, or formed from fog (n.1) + -y (2). Foggy Bottom "U.S. Department of State," from the name of a marshy region of Washington, D.C., where many federal buildings are (also with a suggestion of political murkiness) popularized 1947 by James Reston in "New York Times," but he said it had been used earlier by Edward Folliard of "The Washington Post."
foghorn (n.) Look up foghorn at Dictionary.com
1858, from fog (n.1) + horn (n.).
foible (n.) Look up foible at Dictionary.com
1640s, "weak point of a sword blade" (contrasted to forte), from French foible (n.), from obsolete foible (adj.) "weak," from Old French foible "feeble," dissimilated from Lain flebilis (see feeble). Extended sense of "weak point of character" is first recorded 1670s. Related: Foibles.
foie gras (n.) Look up foie gras at Dictionary.com
1818, short for pâté de foie gras (see pate (n.2)). Pâté de foie gras (1827 in English) is literally "pie of fat liver;" originally served in a pastry (as still in Alsace), the phrase now chiefly in English with reference to the filling.
foil (v.) Look up foil at Dictionary.com
c.1300, foilen "to spoil a trace or scent by running over it," irregularly from Old French fouler "trample," from Vulgar Latin *fullare "to clean cloth" (by treading on it), from Latin fullo "one who cleans cloth, fuller," of unknown origin.

Hence, "to overthrow, defeat" (1540s). Sense of "frustrate the efforts of" first recorded 1560s. Related: Foiled; foiling. Foiled again! as a cry of defeat and dismay is from at least 1847.
foil (n.) Look up foil at Dictionary.com
"thin sheet of metal," early 14c., from Old French fueille "leaf," from Latin folia "leaves," plural (mistaken for fem. singular) of folium "leaf" (see folio).

The sense of "one who enhances another by contrast" (1580s) is from the practice of backing a gem with metal foil to make it shine more brilliantly. The meaning "light sword used in fencing" (1590s) could be from this sense, or from foil (v.). The modern sense of "metallic food wrap" is from 1946.
foist (v.) Look up foist at Dictionary.com
1540s, from Dutch vuisten "take in hand," from Middle Dutch vuist "fist" (see fist). Earliest sense was cheating at dice by concealing a loaded one in the palm of the hand with the intention of introducing it into play; meaning "introduce surreptitiously" is from 1560s. Related: Foisted; foisting.
Fokker Look up Fokker at Dictionary.com
German monoplane, 1913, from name of A.H.G. Fokker (1890-1939), Dutch engineer and inventor.
fold (v.) Look up fold at Dictionary.com
Old English faldan (Mercian), fealdan (West Saxon), transitive, "to bend cloth back over itself," class VII strong verb (past tense feold, past participle fealden), from Proto-Germanic *falthan, *faldan (cognates: Middle Dutch vouden, Dutch vouwen, Old Norse falda, Middle Low German volden, Old High German faldan, German falten, Gothic falþan).

The Germanic words are from PIE *pel-to- (cognates: Sanskrit putah "fold, pocket," Albanian pale "fold," Middle Irish alt "a joint," Lithuanian pleta "I plait"), from root *pel- (3) "to fold" (also source of Greek ploos "fold," Latin -plus).

The weak form developed from 15c. In late Old English also of the arms. Intransitive sense, "become folded" is from c.1300 (of the body or limbs); earlier "give way, fail" (mid-13c.). Sense of "to yield to pressure" is from late 14c. Related: Folded; folding.
fold (n.1) Look up fold at Dictionary.com
"pen or enclosure for sheep or other domestic animals," Old English falæd, falud "stall, stable, cattle-pen," a general Germanic word (cognates: East Frisian folt "enclosure, dunghill," Dutch vaalt "dunghill," Danish fold "pen for sheep"), of uncertain origin. Figurative use by mid-14c.
fold (n.2) Look up fold at Dictionary.com
"a bend or ply in anything," mid-13c., from fold (v.).
fold-out (n.) Look up fold-out at Dictionary.com
1961, from fold (v.) + out.
folder (n.) Look up folder at Dictionary.com
1550s as "one who folds;" 1911 as "folding cover for loose papers;" agent noun from fold (v.).
foliage (n.) Look up foliage at Dictionary.com
mid-15c., from Middle French feuillage, from Old French feuille "leaf" (see foil (n.)). The form has altered by influence of Latin folium.
foliate (adj.) Look up foliate at Dictionary.com
1620s, from Latin foliatus "leaved, leafy," from folium (see folio).
foliate (v.) Look up foliate at Dictionary.com
1660s, "to apply silver leaf," from Latin foliatus "leaved, leafy," from folium (see folio). Meaning "to put forth leaves" is from 1775. Related: Foliated; foliating.
foliation (n.) Look up foliation at Dictionary.com
1620s, from French foliation or formed in English from Latin foliatus (see foliate (v.)).