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 *bhulyom "leaf" (cognates: Greek phyllon "leaf," Gaelic bile "leaflet, blossom"), from root *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 *folkom (cognates: Old Frisian folk, Middle Dutch volc, German Volk "people"), from Proto-Germanic *fulka-, 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."

Some have attempted to link the word to Greek plethos "multitude;" Latin plebs "people, mob," populus "people" or vulgus; OED and Klein discount this theory but it is accepted in Watkins. The plural form has been usual since 17c. Superseded in most senses by people. Old English folc was commonly used in forming compounds, such as folccwide "popular saying," folcgemot "town or district meeting;" folcwoh "deception of the public." Folk-etymology is attested from 1890.
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]
folk music Look up folk music at Dictionary.com
1889, from folk (also see folklore). In reference to the branch of modern popular music (originally associated with Greenwich Village in New York City) it dates from 1958.
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
1846, coined by antiquarian William J. Thoms (1803-1885) as an Anglo-Saxonism (replacing popular antiquities) and first published in the "Athenaeum" of Aug. 22, 1846, from 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, as in folk art (1892), folk-hero (1874), folk-medicine (1877), folk-tale/folk tale (1850; Old English folctalu meant "genealogy"), folk-song (1847), 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
1881, from folklore + -ist.
folks (n.) Look up folks at Dictionary.com
"people of one's family," 1715, colloquial, from plural of folk.
folksy (adj.) Look up folksy at Dictionary.com
"sociable, unpretentious," 1852, U.S. colloquial, from folks + -y (2).
folkways (n.) Look up folkways at Dictionary.com
coined 1907 in book of the same name by U.S. sociologist William Graham Sumner (1840-1910), who also is credited with ethnocentrism, found in the same book. 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"]
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., from French follicule or directly from Latin folliculus "little bag," diminutive of follis "bellows, inflated ball," from PIE *bhol-n-, suffixed form of root *bhel- (2) "to blow, swell" (see bole).
follies (n.) Look up follies at Dictionary.com
"revue with glamorous female performers," 1908, 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
Old English folgian, fylgan "follow, accompany; follow after, pursue," also "obey, apply oneself to a practice 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. 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].
follow up (n.) Look up follow up at Dictionary.com
also follow-up, 1923, originally in the argot of personnel management, from verbal phrase follow up (1847).
follow-through (n.) Look up follow-through at Dictionary.com
1897, of golf swings, from verbal phrase follow through. Figurative use from 1926.
follower (n.) Look up follower at Dictionary.com
Old English folgere "retainer, servant, disciple; successor," agent noun from follow. Related: Followers.
following (n.) Look up following at Dictionary.com
c.1300, verbal noun from follow (v.). Meaning "a body of disciples or retainers" is from mid-15c.
folly (n.) Look up folly at Dictionary.com
early 13c., "mental weakness; unwise conduct" (in Middle English including wickedness, lewdness, madness), from Old French folie (12c.) "folly, madness, stupidity," from fol (see fool (n.)). Sense of "costly structure considered to have shown folly in the builder" is attested from 1650s. Used since Middle English of place names, especially country estates, as a form of Old French folie in its meaning "delight." Meaning "glamorous theatrical revue with lots of pretty girls" is from 1880, from French.
Fomalhaut Look up Fomalhaut at Dictionary.com
bright star in the constellation Piscis Austrinis, 1594, from Arabic Fum al Hut "the Fish's Mouth," which describes its position in the imaginary star-picture.
foment (v.) Look up foment at Dictionary.com
early 15c., "apply hot liquids," from Old French fomenter (13c.) "apply hot compress (to a wound)," from Late Latin fomentare, from Latin fomentum "warm application, poultice," contraction of *fovimentum, from fovere "to warm; cherish, encourage" (see fever). Extended sense of "stimulate, instigate" (1620s) was in the French. Related: Fomented; fomenting.
fomentation (n.) Look up fomentation at Dictionary.com
c.1400, from Late Latin fomentationem, noun of action from past participle stem of fomentare, from Latin fomentum (see foment).
Fomorian Look up Fomorian at Dictionary.com
pertaining to the monstrous race in Irish mythology, 1876, from Irish fomor "pirate, monster," from fo "under" + mor "sea." Cognate with Gaelic famhair.
fond (adj.) Look up fond at Dictionary.com
mid-14c., originally "foolish, silly," from past tense of fonnen "to fool, be foolish," perhaps from Middle English fonne "fool" (early 14c.), of uncertain origin; or possibly related to fun.

Meaning evolved by 1590 via "foolishly tender" to "having strong affections for." Another sense of fonne was "to lose savor," which may be the original meaning of the word (as in Wyclif: "Gif þe salt be fonnyd it is not worþi," c.1380). Related: Fonder; fondest.
fondant (n.) Look up fondant at Dictionary.com
1877, from French fondant, noun use of present participle of fondre "to melt" (see found (v.2)).
fondle (v.) Look up fondle at Dictionary.com
1690s, "treat with indulgence and affection," frequentative of fond "dote upon" (see fond). Sense of "caress" first recorded 1796. Related: Fondled; fondling (1670s as a past participle adjective).
fondly (adj.) Look up fondly at Dictionary.com
mid-14c., "foolishly," from fond + -ly (2). Meaning "affectionately" is from 1590s.
fondness (n.) Look up fondness at Dictionary.com
late 14c., from fond + -ness.
fondue Look up fondue at Dictionary.com
1878, French cooking term (15c.), literally "melted," properly fem. past participle of fondre "to melt" (see found (v.2)).
font (n.1) Look up font at Dictionary.com
"basin," Old English font, from Latin fons (genitive fontis) "fountain" (see fountain), especially in Medieval Latin fons baptismalis "baptismal font."
font (n.2) Look up font at Dictionary.com
"typeface, set of letters of a particular type," 1680s, earlier "a casting" (1570s), from Middle French fonte "a casting," noun use of fem. past participle of fondre "to melt" (see found (v.2)). So called because all the letters in a given set were cast at the same time.
fontanelle (n.) Look up fontanelle at Dictionary.com
also fontanel, 1540s, "hollow between two muscles," from French fontanelle (16c.), from Old French fontenele "small source, fountain, spring; fontanelle," diminutive of fontaine "spring" (see fountain), on analogy of the dent in the earth where a spring arises. In reference to the "hollow" in a baby's skull, it is first recorded 1741.
food (n.) Look up food at Dictionary.com
Old English foda "food, nourishment; fuel," also figurative, from Proto-Germanic *fodon (cognates: Gothic fodeins), from Germanic root *fod-, equivalent of PIE *pa- "to tend, keep, pasture, to protect, to guard, to feed" (cognates: Greek pateisthai "to feed;" Latin pabulum "food, fodder," panis "bread," pasci "to feed," pascare "to graze, pasture, feed," pastor "shepherd," literally "feeder;" Avestan pitu- "food;" Old Church Slavonic pasti "feed cattle, pasture;" Russian pishcha "food").

Food chain is from 1917. Food poisoning attested by 1864; food processor in the kitchen appliance sense from 1973.
foodie (n.) Look up foodie at Dictionary.com
"gourmet," 1982, from food + -ie.
foodstuff (n.) Look up foodstuff at Dictionary.com
1870, from food + stuff (n.). Related: Foodstuffs.
fool (n.) Look up fool at Dictionary.com
late 13c., "silly or stupid person," from Old French fol "madman, insane person; idiot; rogue; jester," also "blacksmith's bellows," also an adjective meaning "mad, insane" (12c., Modern French fou), from Latin follis "bellows, leather bag" (see follicle); in Vulgar Latin used with a sense of "windbag, empty-headed person." Compare also Sanskrit vatula- "insane," literally "windy, inflated with wind."
The word has in mod.Eng. a much stronger sense than it had at an earlier period; it has now an implication of insulting contempt which does not in the same degree belong to any of its synonyms, or to the derivative foolish. [OED]
Meaning "jester, court clown" first attested late 14c., though it is not always possible to tell whether the reference is to a professional entertainer or an amusing lunatic on the payroll. As the name of a kind of custard dish, it is attested from 1590s (the food also was called trifle, which may be the source of the name).
There is no foole to the olde foole [Heywood, 1546]
Feast of Fools (early 14c.), from Medieval Latin festum stultorum) refers to the burlesque festival celebrated in some churches on New Year's Day in medieval times. Fool's gold "iron pyrite" is from 1829. Fool's paradise "state of illusory happiness" is from mid-15c. Foolosopher, a most useful insult, turns up in a 1549 translation of Erasmus. Fool's ballocks is described in OED as "an old name" for the green-winged orchid.
fool (v.) Look up fool at Dictionary.com
mid-14c., "to be foolish, act the fool," from fool (n.). The meaning "to make a fool of" is recorded from 1590s. Also as a verb 16c.-17c. was foolify. Related: Fooled; fooling. Fool around is 1875 in the sense of "pass time idly," 1970s in sense of "have sexual adventures."
fool (adj.) Look up fool at Dictionary.com
"foolish, silly," considered modern U.S. colloquial, but it is attested from early 13c., from fool (n.).
foolery (n.) Look up foolery at Dictionary.com
1550s, from fool (n.) + -ery.
foolhardy (adj.) Look up foolhardy at Dictionary.com
early 13c., from fool (n.) + Middle English hardi "bold;" hence "foolishly brave" (see hardy). Compare Old French fol hardi.
foolish (adj.) Look up foolish at Dictionary.com
early 14c., from fool (n.) + -ish. Related: Foolishly; foolishness. Old English words for this were dysig, stunt, dol.
foolproof (adj.) Look up foolproof at Dictionary.com
also fool-proof, 1902, American English, "safe against the incompetence of a fool," from fool (n.) + proof.
foolscap (n.) Look up foolscap at Dictionary.com
literally "fool's cap; cap worn by jesters," 1630s; c.1700 as a type of paper, so called because this type of paper originally was watermarked with a court jester's cap.
foosball (n.) Look up foosball at Dictionary.com
debuted in U.S. 1963 and was a craze on some college campuses for a few years thereafter. Said to have been designed c.1930s in Switzerland. The name is presumably from the pronunciation of Fußball, the German form of (Association) football.
foot (n.) Look up foot at Dictionary.com
Old English fot, from Proto-Germanic *fot (cognates: Old Saxon fot, Old Norse fotr, Dutch voet, Old High German fuoz, German Fuß, Gothic fotus "foot"), from PIE *ped- (cognates: Avestan pad-; Sanskrit pad-, accusative padam "foot;" Greek pos, Attic pous, genitive podos; Latin pes, genitive pedis "foot;" Lithuanian padas "sole," peda "footstep"). Plural form feet is an instance of i-mutation. Of a bed, grave, etc., first recorded c.1300.

The linear measurement of 12 inches was in Old English, from the length of a man's foot. Colloquial exclamation my foot! expressing "contemptuous contradiction" [OED] is first attested 1923, probably a euphemism for my ass, in the same sense, which dates back to 1796 (also see eyewash). The metrical foot (Old English, translating Latin pes, Greek pous in the same sense) is commonly taken as a reference to keeping time by tapping the foot.

To get off on the right foot is from 1905; to put one's best foot foremost first recorded 1849 (Shakespeare has the better foot before, 1596). To put one's foot in (one's) mouth "say something stupid" is attested by 1942; the expression put (one's) foot in something "make a mess of it" is from 1823.
foot (v.) Look up foot at Dictionary.com
c.1400, "dance, move on foot," from foot (n.). To foot a bill is attested from 1848, from the process of tallying the expenses and writing the figure at the bottom ("foot") of the bill.
footage (n.) Look up footage at Dictionary.com
1892, "piece work system to pay miners;" 1916, "the length of film used in a scene, etc.," from foot (n.) as a measure of length + -age.
football (n.) Look up football at Dictionary.com
open-air game, first recorded c.1400; see foot (n.) + ball (n.1). Forbidden in a Scottish statute of 1424. The first reference to the ball itself is late 15c. Figurative sense of "something idly kicked around" is first recorded 1530s. Ball-kicking games date back to the Roman legions, at least, but the sport seems to have risen to a national obsession in England, c.1630. Rules first regularized at Cambridge, 1848; soccer (q.v.) split off in 1863.

The U.S. style (known to some in England as "stop-start rugby with padding") evolved gradually 19c.; the first true collegiate game is considered to have been played Nov. 6, 1869, between Princeton and Rutgers, at Rutgers, but the rules there were more like soccer. A rematch at Princeton Nov. 13, with the home team's rules, was true U.S. football. The earliest recorded application of the word football to this is from 1881.
footer (n.) Look up footer at Dictionary.com
c.1600, "pedestrian;" 1781, "a kick at football;" 1863, British student slang, "the game of football;" see foot (n.), football, -er.