fibrosis (n.) Look up fibrosis at Dictionary.com
1873, a Modern Latin hybrid, from Latin fibra (see fiber) + Greek suffix -osis.
fibrous (adj.) Look up fibrous at Dictionary.com
1620s, from Modern Latin fibrosus, from Latin fibra (see fiber).
fibula (n.) Look up fibula at Dictionary.com
1670s, "clasp, buckle, brooch;" 1706 as "smaller bone in the lower leg," from Latin fibula "clasp, brooch," related to figere "to fasten, fix" (see fix (v.)).

Used in reference to the outer leg bone as a loan-translation of Greek perone "small bone in the lower leg," originally "clasp, brooch; anything pointed for piercing or pinning;" the bone was so called because it resembles a clasp like a modern safety pin.
fiche (n.) Look up fiche at Dictionary.com
1949, "slip of paper, form," from French fiche "card, index card, slip, form," from Old French fichier "to attach, stick into, pin on," from Vulgar Latin *figicare, from Latin figere "to fix, fasten" (see fix (v.)). Sense of "card, strip of film" is a shortening of microfiche (1950).
fichu (n.) Look up fichu at Dictionary.com
1803, from French fichu (18c. in this sense), apparently a noun use of the adjective fichu "carelessly thrown on," from Latin figere "to fasten" (see fix (v.)). "[M]od. substitution for a coarser word" [Weekley].
fickle (adj.) Look up fickle at Dictionary.com
c.1200, probably from Old English ficol "deceitful, cunning, tricky," related to befician "deceive," and to facen "deceit, treachery." Common Germanic (compare Old Saxon fekan "deceit," Old High German feihhan "deceit, fraud, treachery"), from PIE *peig- (2) "evil-minded, treacherous, hostile" (see foe). Sense of "changeable" is first recorded late 13c. Related: Fickleness.
fiction (n.) Look up fiction at Dictionary.com
late 14c., "something invented," from Old French ficcion (13c.) "dissimulation, ruse; invention," and directly from Latin fictionem (nominative fictio) "a fashioning or feigning," noun of action from past participle stem of fingere "to shape, form, devise, feign," originally "to knead, form out of clay," from PIE *dheigh- "to build, form, knead" (source also of Old English dag "dough;" see dough). As a branch of literature, 1590s.
fictional (adj.) Look up fictional at Dictionary.com
"pertaining to fiction," 1843, from fiction + -al (1). Earlier fictitious also was used in this sense (1773).
fictionalization (n.) Look up fictionalization at Dictionary.com
1946, noun of action from fictionalize.
fictionalize (v.) Look up fictionalize at Dictionary.com
1925, from fictional + -ize. Related: Fictionalized; fictionalizing.
fictitious (adj.) Look up fictitious at Dictionary.com
1610s, "artificial, counterfeit," from Medieval Latin fictitus, a misspelling of Latin ficticius "artificial, counterfeit," from fictus "feigned, fictitious, false," past participle of fingere (see fiction). Related: Fictitiously.
ficus (n.) Look up ficus at Dictionary.com
c.1400, from Latin ficus "fig, fig tree" (see fig).
fiddle (n.) Look up fiddle at Dictionary.com
late 14c., fedele, earlier fithele, from Old English fiðele, which is related to Old Norse fiðla, Middle Dutch vedele, Dutch vedel, Old High German fidula, German Fiedel; all of uncertain origin. Perhaps from Medieval Latin vitula "stringed instrument," which is perhaps related to Latin vitularia "celebrate joyfully," from Vitula, Roman goddess of joy and victory, who probably, like her name, originated among the Sabines [Klein, Barnhart]. Unless the Medieval Latin word is from the Germanic ones.
FIDDLE, n. An instrument to tickle human ears by friction of a horse's tail on the entrails of a cat. [Ambrose Bierce, "The Cynic's Word Book," 1906]
Fiddle has been relegated to colloquial usage by its more proper cousin, violin, a process encouraged by phraseology such as fiddlesticks, contemptuous nonsense word fiddlededee (1784), and fiddle-faddle. Fit as a fiddle is from 1610s.
fiddle (v.) Look up fiddle at Dictionary.com
late 14c., from fiddle (n.); the figurative sense of "to act nervously or idly" is from 1520s. Related: Fiddled; fiddling.
fiddle-faddle Look up fiddle-faddle at Dictionary.com
1570s (n.); 1630s (v.), apparently a reduplication of obsolete faddle "to trifle."
fiddlehead (n.) Look up fiddlehead at Dictionary.com
"one with a head as hollow as a fiddle," 1854 (fiddleheaded), from fiddle (n.) + head (n.). As a name for young fern fronds, from 1882, from resemblance to a violin's scroll.
fiddler (n.) Look up fiddler at Dictionary.com
late 13c., from Old English fiðelere "fiddler" (fem. fiðelestre), agent noun from fiddle (v.). Fiddler's Green first recorded 1825, from sailors' slang. Fiddler crab is from 1714.
fiddlestick (n.) Look up fiddlestick at Dictionary.com
15c., originally "the bow of a fiddle," from fiddle (n.) and stick (n.). Meaning "nonsense" (usually fiddlesticks) is from 1620s.
fideism (n.) Look up fideism at Dictionary.com
1885, from Latin fides "faith" (see faith) + -ism.
fidelity (n.) Look up fidelity at Dictionary.com
early 15c., from Middle French fidélité (15c.), from Latin fidelitatem (nominative fidelitas) "faithfulness, adherence," from fidelis "faithful, true," from fides "faith" (see faith).
fidget (n.) Look up fidget at Dictionary.com
1670s, as the fidget "uneasiness," later the fidgets, from a 16c. verb fidge "move restlessly," perhaps from Middle English fiken "to fidget, hasten," from Old Norse fikjask "to desire eagerly" (source also of German ficken "to move about briskly;" see fuck).
fidget (v.) Look up fidget at Dictionary.com
1670s (implied in fidgetting); see fidget (n.). Related: Fidgeted.
fidgety (adj.) Look up fidgety at Dictionary.com
1730s, from fidget (n.) + -y (2). Related: Fidgetiness.
fiducial (adj.) Look up fiducial at Dictionary.com
1570s, from Latin fiducialis "reliable," from fiducia "trust" (see faith).
fiduciary (adj.) Look up fiduciary at Dictionary.com
1630s, from Latin fiduciarius "(holding) in trust," from fiducia "trust" from root of fidere "to trust" (see faith). In Roman law, fiducia was "a right transferred in trust;" paper currency sense (1878) is because its value depends on the trust of the public. As a noun, from 1630s.
fie (interj.) Look up fie at Dictionary.com
late 13c., possibly from Old French fi, exclamation of disapproval, and reinforced by a Scandinavian form (compare Old Norse fy); it's a general sound of disgust that seems to have developed independently in many languages.
fief (n.) Look up fief at Dictionary.com
also feoff, 1610s, from French fief (12c.) "possession, holding, domain; feudal duties, payment," from Medieval Latin feodum "land or other property whose use is granted in return for service," widely said to be from Frankish *fehu-od "payment-estate," or a similar Germanic compound, in which the first element is cognate with Old English feoh "money, movable property, cattle" (see fee), from PIE *peku- "cattle" (cognates: Sanskrit pasu, Lithuanian pekus "cattle;" Latin pecu "cattle," pecunia "money, property"); second element similar to Old English ead "wealth" (see Edith).
fiefdom (n.) Look up fiefdom at Dictionary.com
1814, from fief + -dom.
field (n.) Look up field at Dictionary.com
Old English feld "plain, open land" (as opposed to woodland), also "a parcel of land marked off and used for pasture or tillage," probably related to Old English folde "earth, land," from Proto-Germanic *felthuz "flat land" (common West Germanic, cognates: Old Saxon and Old Frisian feld "field," Old Saxon folda "earth," Middle Dutch velt, Dutch veld Old High German felt, German Feld "field," but not found outside it; Swedish fält, Danish felt are borrowed from German), from PIE *pel(e)-tu-, from root *pele- (2) "flat, to spread" (see plane (n.1)).

Finnish pelto "field" is believed to have been adapted from Proto-Germanic. The English spelling with -ie- probably is the work of Anglo-French scribes (compare brief, piece). Collective use for "all engaged in a sport" (or, in horseracing, all but the favorite) is 1742; play the field "avoid commitment" (1936) is from notion of gamblers betting on other horses than the favorite. Field glasses attested by 1836.
field (v.) Look up field at Dictionary.com
"to go out to fight," 16c., from field (n.) in the specific sense of "battlefield" (Old English). The meaning "to stop and return the ball" is first recorded 1823, originally in cricket; figurative sense is from 1902. Related: Fielded; fielding.
field day (n.) Look up field day at Dictionary.com
1747, originally a day of military exercise and review (see field (v.)); figurative sense is from 1827.
fielder (n.) Look up fielder at Dictionary.com
early 14c., "one who works in a field," agent noun from field (n.). Sporting sense is from 1832 (in cricket; by 1868 in baseball).
fielding (n.) Look up fielding at Dictionary.com
1823 in cricket (by 1884 in baseball), verbal noun from field (v.).
fieldstone (n.) Look up fieldstone at Dictionary.com
1797, from field (n.) + stone (n.).
fiend (n.) Look up fiend at Dictionary.com
Old English feond "enemy, foe," originally present participle of feogan "to hate," from Proto-Germanic *fijand- "hating, hostile" (cognates: Old Frisian fiand "enemy," Old Saxon fiond, Middle Dutch viant, Dutch vijand "enemy," Old Norse fjandi, Old High German fiant, Gothic fijands), from suffixed form of PIE root *pe(i)- "to hurt" (source also of Gothic faian "to blame;" see passion).

As spelling suggests, it was originally the opposite of friend, but the word began to be used in Old English for "Satan" (as the "enemy of mankind"), which shifted its sense to "diabolical person" (early 13c.). The old sense of the word devolved to foe, then to the imported word enemy. For spelling with -ie- see field. Meaning "devotee (of whatever is indicated)," as in dope fiend, is from 1865.
fiendish (adj.) Look up fiendish at Dictionary.com
1520s, from fiend + -ish. Related: Fiendishly; fiendishness.
fierce (adj.) Look up fierce at Dictionary.com
mid-13c., "proud, noble, bold," from Old French fers, nominative form of fer, fier "strong, overwhelming, violent, fierce, wild; proud, mighty, great, impressive" (Modern French fier "proud, haughty"), from Latin ferus "wild, untamed," from PIE root *ghwer- "wild, wild animal" (cognates: Greek ther, Old Church Slavonic zveri, Lithuanian zveris "wild beast").

Original English sense of "brave, proud" died out 16c., but caused the word at first to be commonly used as an epithet, which accounts for the rare instance of a French word entering English in the nominative case. Meaning "ferocious, wild, savage" is from c.1300. Related: Fiercely; fierceness.
fieri facias Look up fieri facias at Dictionary.com
writ concerning a sum awarded in judgment (often requiring seizure and sale of property for debt), Latin, literally "cause it to be done," the first words of the writ.
fiery (adj.) Look up fiery at Dictionary.com
late 13c., from Middle English fier "fire" (see fire (n.)) + -y (2). The spelling is a relic of one of the attempts to render Old English "y" in fyr in a changing system of vowel sounds. Related: Fieriness.
fiesta (n.) Look up fiesta at Dictionary.com
1844, Spanish, literally "feast" (see feast (n.)).
FIFA Look up FIFA at Dictionary.com
1915, acronym from Fédération Internationale de Football Association, founded 1904 in Paris.
fife (n.) Look up fife at Dictionary.com
1550s, from German Pfeife "fife, pipe," from Old High German pfifa, or via Middle French fifre (15c.) from the same Old High German word; ultimately imitative. German musicians provided music for most European courts in those days. As a verb from 1590s. Agent noun fifer is recorded earlier (1530s). Fife and drum is from 1670s.
fifteen (n.) Look up fifteen at Dictionary.com
Old English fiftyne, from fif "five" (see five) + tyne (see -teen). Cognate with Old Saxon fiftein, Old Frisian fiftine, Old Norse fimtan, Swedish femton, Dutch vijftien, German fünfzehn, Gothic fimftaihun "fifteen." French quinze, Italian quindici "fifteen" are from Latin quindecim (see Quatorze).
fifteenth (adj.) Look up fifteenth at Dictionary.com
late 14c., from fifteen + -th (1). By 15c. displacing forms derived from Old English fifteoða. Compare Old Frisian fiftuda, Dutch vijftiende, German fünfzehnte, Old Norse fimmtandi, Gothic fimftataihunda.
fifth (adj.) Look up fifth at Dictionary.com
c.1200, fift, from Old English fifta, from fif "five" (see five) + -ta (see -th (1)). Altered 14c. by influence of fourth. Compare Old Frisian fifta, Old Saxon fifto, Old Norse fimmti, Dutch vijfde, Old High German fimfto, German fünfte, Gothic fimfta.

Noun meaning "fifth part of a gallon of liquor" is first recorded 1938, American English. Fifth Avenue (in New York City) has been used figuratively for "elegance, taste" since at least 1858. Fifth wheel "superfluous person or thing" first attested 1902. Fifth-monarchy-man, 17c. for "anrachist zealot," is a reference to Dan. ii:44.
fifth column (n.) Look up fifth column at Dictionary.com
1936, from Gen. Emilio Mola's comment at the siege of Madrid during the Spanish Civil War that he would take the city with his four columns of troops outside it and his "fifth column" (quinta columna) in the city.
fifties (n.) Look up fifties at Dictionary.com
1826 as the years of someone's life between 50 and 59; 1853 as the sixth decade of years in a given century. See fifty.
fiftieth (adj.) Look up fiftieth at Dictionary.com
Old English fiftigoða; see fifty + -th (1). Compare Old Norse fimmtugande, and, with a different suffix, Old Frisian fiftichsta, Dutch vijftigste, Old High German fimfzugsto, German fünfzigste.
fifty (n.) Look up fifty at Dictionary.com
Old English fiftig, from fif "five" (see five) + -tig "group of ten" (see -ty (1)). Compare Old Frisian fiftich, Old Norse fimm tigir, Dutch vijftig, Old High German fimfzug, German fünfzig, Gothic fimf tigjus. U.S. colloquial fifty-fifty "in an even division" is from 1913.
fig (n.) Look up fig at Dictionary.com
early 13c., from Old French figue (12c.), from Old Provençal figa, from Vulgar Latin *fica, from Latin ficus "fig tree, fig," which, with Greek sykon, Armenian t'uz is "prob. fr. a common Mediterranean source" [Buck], possibly a Semitic one (compare Phoenician pagh "half-ripe fig"). A reborrowing of a word that had been taken directly from Latin as Old English fic.

The insulting sense of the word in Shakespeare, etc. (A fig for ...) is 1570s, in part from fig as "small, valueless thing," but also from Greek and Italian use of their versions of the word as slang for "vulva," apparently because of how a ripe fig looks when split open [Rawson, Weekley]. Giving the fig (French faire la figue, Spanish dar la higa) was an indecent gesture of ancient provenance, made by putting the thumb between two fingers or into the mouth, with the intended effect of the modern gesture of "flipping the bird" (see bird (n.3)). Also compare sycophant. Use of fig leaf in figurative sense of "flimsy disguise" (1550s) is from Gen. iii:7.