foe (n.) Look up foe at Dictionary.com
Old English gefea, gefa "foe, enemy, adversary in a blood feud" (the prefix denotes "mutuality"), from adjective fah "at feud, hostile," also "guilty, criminal," from Proto-Germanic *faihaz (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.
foe-man (n.) Look up foe-man at Dictionary.com
also foeman, "active enemy," late Old English fah-man; see foe + man (n.).
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 (transitive), from fog (n.1). Intransitive use from 1849. Related: Fogged; fogging.
fog (n.1) Look up fog at Dictionary.com
"thick, obscuring mist," 1540s, a back-formation from foggy (which appeared about the same time) or from a Scandinavian source akin to Danish fog "spray, shower, snowdrift," Old Norse fjuk "drifting snow storm." Compare also Old English fuht, Dutch vocht, German Feucht "damp, moist." Figurative phrase in a fog "at a loss what to do" first recorded c.1600. Fog-lights is from 1962.
fog (n.2) Look up fog at Dictionary.com
"long grass, second growth of grass after mowing," late 14c., probably of Scandinavian origin; compare Norwegian fogg "long grass in a moist hollow," Icelandic fuki "rotten sea grass." A 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- (2) "to rot, decay" (see foul (adj.)).
fog-horn (n.) Look up fog-horn at Dictionary.com
1844, from fog (n.1) + horn (n.).
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 (1772) "old-fashioned," also "old-fashioned person;" or from fog (n.2) in an obsolete senses of "moss," or from foggy "bloated, fat" (1520s), which perhaps is an extended sense of fog (n.2). Related: Fogeydom; fogeyish; fogeyism.
foggy (adj.) Look up foggy at Dictionary.com
1540s, of the air, "full of thick mist," perhaps from a Scandinavian source, or formed from fog (n.1) + -y (2). Foggy Bottom "U.S. Department of State," is 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."
foible (n.) Look up foible at Dictionary.com
1640s, "weak point of a sword blade" (contrasted to forte), from French foible "a weak point, a weakness, failing," from noun use of Old French adjective feble "feeble" (see feeble). The spelling borrowed in English is obsolete in modern French, which uses faible. Extended sense of "weak point of character" is first recorded 1670s. Related: Foibles.
foie-gras (n.) Look up foie-gras at Dictionary.com
1818, French, short for pâté de foie gras (1827 in English), 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. French foie "liver" is cognate with Italian fegato, from Latin *ficatum. For pâté see pate (n.2); for gras see grease (n.).
foil (v.1) Look up foil at Dictionary.com
c.1300, foilen "to spoil a trace or scent by running over it" (more commonly defoilen), irregularly from Old French foler, fuler "trample on, injure, maim; ill-treat, deceive, get the better of" (13c., Modern French fouler), from Vulgar Latin *fullare "to clean cloth" (by treading on it), from Latin fullo "one who cleans cloth, a fuller," of unknown origin. Compare full (v.).

Hence, "to overthrow, defeat" (1540s; as a noun in this sense from late 15c.); "frustrate the efforts of" (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
"very thin sheet of metal," early 14c., foile, from Old French foil, fueill, fueille "leaf; foliage; sheet of paper; sheet of metal" (12c., Modern French fueille), from Latin folia, 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 sense of "metallic food wrap" is from 1946.
foil (v.2) Look up foil at Dictionary.com
"apply foil to," 1610s, from foil (n.1).
foist (v.) Look up foist at Dictionary.com
1540s, probably from Dutch vuisten "take in hand," from Middle Dutch vuist "fist" (see fist (n.)). 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; general meaning "introduce surreptitiously, work in by a trick" is from 1560s. Related: Foisted; foisting.
Fokker (n.) Look up Fokker at Dictionary.com
German monoplane of World War I, 1913, from name of Anton "Anthony" H.G. Fokker (1890-1939), Dutch engineer and inventor who started his aircraft manufacturing business in Germany in 1912.
fold (v.) Look up fold at Dictionary.com
Old English faldan (Mercian), fealdan (West Saxon), transitive, "to bend (cloth) back over itself, wrap up, furl," 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).

Of the arms, from late Old English. Intransitive sense "become doubled upon itself" is from c.1300 (of the body); earlier "give way, fail" (mid-13c.). Sense of "to yield to pressure" is from late 14c. The weak conjugation developed from 15c. 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.). Compare similarly formed Middle Dutch voude, Dutch vouw, Old High German falt, German Falte, Old Norse faldr.
fold-out (n.) Look up fold-out at Dictionary.com
larger page, inserted folded, in a book, magazine, etc., 1961, from fold (v.) + out (adv.).
folder (n.) Look up folder at Dictionary.com
1550s, "one who folds;" 1903, "folding cover for loose papers" (earlier as "a fold-up document," often a railway timetable or map); agent noun from fold (v.).
foliage (n.) Look up foliage at Dictionary.com
mid-15c., "representation of leaves or branches" (as an ornamental design), from Middle French feuillage, from Old French feuille "leaf, foliage" (see foil (n.)). The form has altered 17c. by influence of Latin folium or its derivatives in English.
foliate (adj.) Look up foliate at Dictionary.com
1620s, "beaten into thin sheets," from Medieval Latin foliatus "leaved, leafy," from Latin folium "a leaf" (see folio). As "leaf-like" from 1650s.
foliate (v.) Look up foliate at Dictionary.com
1660s (implied in foliated), "to apply silver leaf," from Medieval Latin foliatus "leaved, leafy," from Latin folium "a leaf" (see folio). Meaning "put forth leaves" is from 1775. Related: Foliated; foliating.
foliation (n.) Look up foliation at Dictionary.com
1620s, from Latin foliat-, stem of folium "a leaf" (see folio).
folic (adj.) Look up folic at Dictionary.com
1941, in folic acid, coined from Latin folium "a leaf" (see folio) + -ic. So called for its abundance in green leaves, such as those of spinach.
folio (n.) Look up folio at Dictionary.com
mid-15c., from Late Latin folio "leaf or sheet of paper," from Latin folio, ablative of folium "leaf," from PIE *bhol-yo- "leaf" (cognates: Greek phyllon "leaf," Gaelic bile "leaflet, blossom"), suffixed form of root *bhel- (3) "to thrive, bloom," which is possibly from *bhel- (2) "to blow, inflate, swell" (see bole). Ablative of location, because this was used in page references. Meaning "volume of the largest size" first attested 1620s.
folium (n.) Look up folium at Dictionary.com
see folio.
folk (n.) Look up folk at Dictionary.com
Old English folc "common people, laity; men; people, nation, tribe; multitude; troop, army," from Proto-Germanic *folkam (cognates: Old Saxon folc, Old Frisian folk, Middle Dutch volc, Dutch volk, Old High German folc, German Volk "people"). Perhaps originally "host of warriors:" Compare Old Norse folk "people," also "army, detachment;" and Lithuanian pulkas "crowd," Old Church Slavonic pluku "division of an army," both believed to have been borrowed from Proto-Germanic. Old English folcstede could mean both "dwelling-place" and "battlefield." According to Watkins, from PIE *ple-go-, suffixed form of root *pele- (1) "to fill," which would make it cognate with Greek plethos "people, multitude." Superseded in most senses by people. Generally a collective noun in Middle English, however plural folks is attested from 15c.

Old English folc was commonly used in forming compounds (59 are listed in the Clark Hall dictionary), such as folccwide "popular saying," folcgemot "town or district meeting;" folcwoh "deception of the public." Modern use of folk as an adjective is from c.1850 (see folklore).
folk music (n.) Look up folk music at Dictionary.com
1889, "music of the people," from folk in the "of the people" sense (also see folklore) + music. In reference to a branch of modern popular music imitative of the simple and artless style of music originating among the common people (originally associated with Greenwich Village in New York City) it dates from 1958.
folk-etymology (n.) Look up folk-etymology at Dictionary.com
1890; see folk (n.) + etymology.
By Folk-etymology is meant the influence exercised upon words, both as to their form and meaning, by the popular use and misuse of them. In a special sense, it is intended to denote the corruption which words undergo, owing either to false ideas about their derivation, or to a mistaken analogy with other words to which they are supposed to be related. [The Rev. A. Smythe Palmer, "Folk-Etymology," 1890]
folkie (n.) Look up folkie at Dictionary.com
"devotee of (modern) folk music," attested by 1966; with -ie.
folklore (n.) Look up folklore at Dictionary.com
"traditional beliefs and customs of the common people," 1846, coined by antiquarian William J. Thoms (1803-1885) as an Anglo-Saxonism (replacing popular antiquities) in imitation of German compounds in Volk- and first published in the "Athenaeum" of Aug. 22, 1846; see folk + lore. Old English folclar meant "homily."

This word revived folk in a modern sense of "of the common people, whose culture is handed down orally," and opened up a flood of compound formations: Folk art (1892), folk-hero (1874), folk-medicine (1877), folk-tale (1850; Old English folctalu meant "genealogy"), folk-song (1847, "a song of the people," translating German Volkslied), folk-singer (1876), folk-dance (1877).
folkloric (adj.) Look up folkloric at Dictionary.com
1883, from folklore + -ic.
folklorist (n.) Look up folklorist at Dictionary.com
also folk-lorist, "one engaged in the study of folklore," 1876, from folklore + -ist.
folks (n.) Look up folks at Dictionary.com
"persons," Middle English, plural of folk (n.). Colloquial sense of "people of one's family" is from 1715. In Old English in plural use it meant only "peoples, nations."
folksy (adj.) Look up folksy at Dictionary.com
"sociable, unpretentious," 1852, U.S. colloquial, from folks + -y (2). Related: Folksiness.
folkways (n.) Look up folkways at Dictionary.com
coined 1906 in a book of the same name by U.S. sociologist William Graham Sumner (1840-1910); see folk (n.) + way (n.).
Folkways are habits of the individual and customs of the society which arise from efforts to satisfy needs. ... Then they become regulative for succeeding generations and take on the character of a social force. [Sumner, "Folkways"]
Sumner also often is credited with ethnocentrism, which is found in the same book but is older.
folky (adj.) Look up folky at Dictionary.com
"characteristic of the common people," 1914, from folk + -y (2). Old English had folcisc "popular, secular, common."
follicle (n.) Look up follicle at Dictionary.com
early 15c., in anatomy, "small sack," from Latin folliculus "a little bag," diminutive of follis "bellows, inflated ball, money-bag," from PIE *bhol-n-, suffixed form of root *bhel- (2) "to blow, swell" (see bole). Related: Follicular.
follies (n.) Look up follies at Dictionary.com
"glamorous theatrical revue with lots of pretty girls," 1880, from French folies (mid-19c.), from folie (see folly), probably in its sense of "extravagance" (compare extravaganza).
follow (v.) Look up follow at Dictionary.com
Middle English folwen, from Old English folgian, fylgian, fylgan "to accompany (especially as a disciple), move in the same direction as; follow after, pursue, move behind in the same direction," also "obey (a rule or law), conform to, act in accordance with; apply oneself to (a practice, trade, or calling)," from Proto-Germanic *fulg- (cognates: Old Saxon folgon, Old Frisian folgia, Middle Dutch volghen, Dutch volgen, Old High German folgen, German folgen, Old Norse fylgja "to follow"). Probably originally a compound, *full-gan, with a sense of "full-going," the sense then shifting to "serve, go with as an attendant" (compare fulfill). Related: Followed; following.

Sense of "accept as leader or guide, obey or be subservient to" was in late Old English. Meaning "come after in time" is from c.1200; meaning "to result from" (as effect from cause) is from c.1200. Meaning "to keep up with mentally, comprehend" is from 1690s. Intransitive sense "come or go behind" is from mid-13c. To follow one's nose "go straight on" first attested 1590s. "The full phrase is, 'Follow your nose, and you are sure to go straight.' " [Farmer]. The children's game follow my leader is attested by that name from 1835.
follow-through (n.) Look up follow-through at Dictionary.com
1897, of golf swings, from verbal phrase follow through; see follow + through. Figurative use from 1926.
follow-up (n.) Look up follow-up at Dictionary.com
1923, originally in the argot of personnel management, from verbal phrase follow up "pursue closely, act on energetically" (1847); see follow (v.) + up (adv.).
follower (n.) Look up follower at Dictionary.com
Old English folgere "retainer, servant, disciple; successor," agent noun from follow. Compare similarly formed Old Frisian folgere, Dutch volger, German Folger. Related: Followers.
following (n.) Look up following at Dictionary.com
late 14c., "action of following, an act of following," verbal noun from follow (v.). Meaning "a body of disciples or retainers" is from mid-15c.; Old English used folgoð in this sense.
folly (n.) Look up folly at Dictionary.com
early 13c., "mental weakness; foolish behavior or character; unwise conduct" (in Middle English including wickedness, lewdness, madness), from Old French folie "folly, madness, stupidity" (12c.), from fol (see fool (n.)). From c.1300 as "an example of foolishness;" sense of "costly structure considered to have shown folly in the builder" is attested from 1650s. But used much earlier, since Middle English, in place names, especially country estates, probably as a form of Old French folie in its meaning "delight." Related: Follies.