Online Etymology Dictionary

footprint (n.): 1550s, from foot (n.) + print (n.). Related: Footprints. Old English had fotspor, fotswæð.
footsie (n.): "amorous play with the feet" [OED], 1944, from foot (n.). Footie in the same sense is from 1935.
footstep (n.): early 13c., "footprint," from foot (n.) + step (n.). Meaning "a tread or fall of the foot" is first attested 1530s. Figurative expression to follow in (someone's) footsteps is from 1540s.
footstool (n.): also foot-stool, 1520s, from foot (n.) + stool. Earlier was fotsceomel, from Old English fotsceamel; for the second element of which see shambles. Figurative sense of "one who is the abject thrall of another" is from 1530s.
fop (n.): mid-15c., "foolish person," of unknown origin, perhaps related to obsolete verb fop "make a fool of," from a continental source akin to German foppen "jeer at, make a fool of." Sense of "dandy, coxcomb, man ostentatiously nice in manner and appearance" is from 1670s, perhaps given in derision by those who thought such things foolish. The 18c. was their period of greatest florescense. The junior variety was a fopling (1680s).
His was the sumptuous age of powder and patches. He was especially dainty in the matters of sword-knots, shoe-buckles, and lace ruffles. He was ablaze with jewelry, took snuff with an incomparable air out of a box studded with diamonds, and excelled in the "nice conduct of a clouded cane." [Charles J. Dunphie, "Fops and Foppery," New York, 1876]
foppery (n.): 1540s, "a foolish action," from fop + -ery. Meaning "behavior and manner of a fop" in the "dandy" sense is from 1690s; meaning "foppish attire" is from 1711.
foppish (adj.): c. 1600, from fop + -ish. Related: Foppishly; foppishness.
for (prep.): Old English for "before, in the sight of, in the presence of; as far as; during, before; on account of, for the sake of; in place of, instead of," from Proto-Germanic *fur "before; in" (source also of Old Saxon furi "before," Old Frisian for, Middle Dutch vore, Dutch voor "for, before;" German für "for;" Danish for "for," før "before;" Gothic faur "for," faura "before"), from PIE *pr- (see fore (adv.)).

From late Old English as "in favor of." For and fore differentiated gradually in Middle English. For alone as a conjunction, "because, since, for the reason that; in order that" is from late Old English, probably a shortening of common Old English phrases such as for þon þy "therefore," literally "for the (reason) that."
for-: prefix usually meaning "away, opposite, completely," from Old English for-, indicating loss or destruction, but in other cases completion, and used as well with intensive or pejorative force, from Proto-Germanic *fur "before, in" (source also of Old Norse for-, Swedish för-, Dutch ver-, Old High German fir-, German ver-); from PIE *pr-, from root *per- (1) "forward, through" (see per).
In verbs the prefix denotes (a) intensive or completive action or process, or (b) action that miscarries, turns out for the worse, results in failure, or produces adverse or opposite results. In many verbs the prefix exhibits both meanings, and the verbs frequently have secondary and figurative meanings or are synonymous with the simplex. [Middle English Dictionary]
Probably originally in Germanic with a sense of "forward, forth," but it spun out complex sense developments in the historical languages. Disused in Modern English. Ultimately from the same root as fore (adv.). From its use in participles it came to be an intensive prefix of adjectives in Middle English (for example Chaucer's forblak "exceedingly black"), but all these now seem to be obsolete.
forage (n.): early 14c. (late 13c. as Anglo-Latin foragium) "food for horses and cattle, fodder," from Old French forrage "fodder; foraging; pillaging, looting" (12c., Modern French fourrage), from fuerre "hay, straw, bed of straw; forage, fodder" (Modern French feurre), from Frankish *fodr "food" or a similar Germanic source, from Proto-Germanic *fodram (source of Old High German fuotar, Old English fodor; see fodder). Meaning "a roving in search of provisions" in English is from late 15c. Military forage cap attested by 1827.
forage (v.): early 15c., "to plunder, pillage," from forage (n.) or from Middle French fourrager. Meaning "hunt about for" is from 1768. Related: Foraged; foraging.
forager (n.): late 14c., "a plunderer," from Old French foragier, from forrage "fodder; pillaging" (see forage (n.)). From early 15c. in English as "one who gathers food for horses and cattle."
foramen (n.): plural foramina, 1670s, from Latin foramen "hole, opening, aperture, orifice," from forare "to pierce" (see bore (v.)).
Foraminifera: 1835, Modern Latin, neuter plural of foraminifer "bearing holes," from Latin foramen "hole, opening, orifice" (see foramen) + -fer "bearing," from ferre "to bear" (see infer). So called because the shells usually are perforated by pores. Related: Foraminiferal.
foraminous (adj.): "full of holes," 1620s, from Late Latin foraminosus, from Latin foramen "hole, opening" (see foramen).
forasmuch (conj.): late 13c., from phrase for as much.
foray (n.): late 14c., "predatory incursion," Scottish, from the verb (14c.), perhaps a back-formation of Middle English forreyer "raider, forager" (mid-14c.), from Old French forrier, from forrer "to forage," from forrage "fodder; foraging; pillaging, looting" (see forage (n.)). Disused by 18c.; revived by Scott. As a verb from 14c.
forb (n.): "broad-leaved herbaceous plant," 1924, from Greek phorbe "fodder, forage."
forbade: past tense of forbid.
forbear (v.): "to abstain," Old English forberan "bear up against, control one's feelings, abstain from, refrain; tolerate, endure" (past tense forbær, past participle forboren), from for- + beran "to bear" (see bear (v.)). Related: Forbearer; forbearing; forbore. Of similar formation are Old High German ferberen, Gothic frabairan "to endure."
forbearance (n.): 1570s, originally legal, in reference to enforcement of debt obligations, from forbear (v.) + -ance. General sense of "a refraining from" is from 1590s.
Forbes: U.S. financial publication, founded 1917 by Scottish-born Wall Street journalist B.C. Forbes (1880-1954) and publisher Walter Drey.
forbid (v.): Old English forbeodan "forbid, prohibit" (past tense forbead, plural forbudon, past participle forboden), from for- "against" + beodan "to command" (see bid (v.)). Common Germanic compound (compare Old Frisian forbiada , Dutch verbieden, Old High German farbiotan, German verbieten, Old Norse fyrirbjoða, Swedish förbjuda, Gothic faurbiudan "to forbid").

In Middle English the past tense was forbad, the plural forbade, the past participle forbode. Related: Forbade; forbidden. Expression God forbid is recorded by early 13c. Forbidden fruit is from Gen. ii:17.
forbidding (adj.): 1570s, "that forbids;" 1712 as "uninviting," present participle adjective from forbid. Related: Forbiddingly; forbiddingness.
forbore: past tense of forbear (v.).
force (n.): c. 1300, "physical strength," from Old French force "force, strength; courage, fortitude; violence, power, compulsion" (12c.), from Vulgar Latin *fortia (source also of Old Spanish forzo, Spanish fuerza, Italian forza), noun use of neuter plural of Latin fortis "strong, mighty; firm, steadfast; brave, bold" (see fort).

Meanings "power to convince the mind" and "power exerted against will or consent" are from mid-14c. Meaning "body of armed men, a military organization" first recorded late 14c. (also in Old French). Physics sense is from 1660s; force field attested by 1920. Related: Forces.
force (v.): c. 1300, forcen, also forsen, "exert force upon (an adversary)," from Old French forcer "conquer by violence," from force "strength, power, compulsion" (see force (n.)). From early 14c. as "to violate (a woman), to rape." From c. 1400 as "compel by force, constrain (someone to do something)." Meaning "bring about by unusual effort" is from 1550s. Card-playing sense is from 1746 (whist). Related: Forced; forcing.
force majeure (n.): 1883, French, literally "superior strength."
force-feed (v.): by 1905 in animal husbandry, from force (n.) + feed (v.). Related: Force-fed; force-feeding. Force-feeding (n.) is from 1900.
forced (adj.): "not spontaneous or voluntary, strained, unnatural," 1570s, past participle adjective from force (v.). Meaning "effected by an unusual application of force" is from 1590s. Related: Forcedly. The flier's forced landing attested by 1917.
forceful (adj.): 1570s, from force (n.) + -ful. Related: Forcefully; forcefulness.
forcemeat (n.): also force-meat, "mincemeat, meat chopped fine and seasoned," 1680s, from force "to stuff," a variant of farce (q.v.) + meat.
forceps (n.): 1560s, from Latin forceps "pair of tongs, pincers," apparently literally "something with which to grasp hot things," a compound of formus "hot" (see warm (adj.)) + root of capere "to hold, take" (see capable). Originally a smith's implement. The classical plural is forcipes. Related: Forcipal.
forcible (adj.): early 15c., "powerful, violent; done by force," from Old French forcible "strong, powerful, mighty," from forcier "conquer by violence" (see force (v.)). From 1550s as "possessing force." Related: Forcibly.
ford (n.): Old English ford "shallow place where water can be crossed," from Proto-Germanic *furduz (source also of Old Frisian forda, Old High German furt, German Furt "ford"), from PIE *prtu- "a going, a passage" (source also of Latin portus "harbor," originally "entrance, passage;" Old Welsh rit, Welsh rhyd "ford;" Old English faran "to go;" see port (n.1)). The line of automobiles (company founded 1903) is named for U.S. manufacturer Henry Ford (1863-1947).
ford (v.): "to cross a body of water by walking on the bottom," 1610s, from ford (n.). Related: Forded; fording.
fordable (adj.): 1610s, from ford (v.) + -able.
fordo (v.): Old English fordon "destroy, ruin, kill," from for- + don (see do (v.)). Related: Fordone; fordoing. The adjective foredone "killed, destroyed" (Old English, Middle English) now is archaic, replaced by done for.
fore (adv., prep.): Old English fore (prep.) "before, in front of, in presence of; because of, for the sake of; earlier in time; instead of;" as an adverb, "before, previously, formerly, once," from Proto-Germanic *fura "before" (source also of Old Saxon fora, Old Frisian fara, Old High German fora, German vor, Danish for, Old Norse fyrr, Gothic faiura "for"), from PIE *prae-, extended form of root *per- (1) "forward, through" (see per).

Now displaced by before. In nautical use, "toward the bows of the ship." Merged from 13c. with the abbreviated forms of afore and before and thus formerly often written 'fore. As a noun, "the front," from 1630s. The warning cry in golf is first recorded 1878, probably a contraction of before.
fore (adj.): mid-15c., "forward;" late 15c., "former, earlier;" early 16c., "situated at the front;" all senses apparently from fore- compounds, which frequently were written as two words in Middle English.
fore-: Middle English for-, fore-, from Old English fore-, often for- or foran-, from fore (adv. & prep.), which was used as a prefix in Old English as in other Germanic languages with a sense of "before in time, rank, position," etc., or designating the front part or earliest time.
fore-and-aft (adj.): nautical, "stem-to-stern," 1610s; see fore + aft. Especially of sails set on the lengthwise line of the vessel (1820), or of vessels so rigged.
fore-brain (n.): 1846, from fore- + brain (n.).
fore-deck (n.): 1560s, from fore- + deck (n.).
fore-mentioned (adj.): also forementioned, 1580s; see fore- + mention (v.). A verb foremention is attested only from 1650s. Old English had foremearcod in this sense.
fore-ordain (v.): also foreordain, "arrange or plan beforehand," late 14c., probably modeled on Latin praeordinare; see fore- + ordain (v.). A hybrid word.
fore-ordained (adj.): also foreordained, early 15c., for-ordenede, past pariticiple of for-ordeinen "to arrange or plan beforehand" (see fore-ordain).
forearm (v.): "prepare for an attack," 1590s, from fore- + arm (v.) "take up weapons." Related: Forearmed; forearming.
forearm (n.): between the elbow and the wrist, 1741, from fore- + arm (n.1).
forebear (n.): "ancestor," late 15c., from fore "before" + be-er "one who exists;" agent noun from be. Originally Scottish. Related: Forebears.