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.
fight (v.) Look up fight at Dictionary.com
Old English feohtan "to fight" (class III strong verb; past tense feaht, past participle fohten), from Proto-Germanic *fehtan (cognates: Old High German fehtan, German fechten, Middle Dutch and Dutch vechten, Old Frisian fiuhta "to fight"), from PIE *pek- (2) "to pluck out" (wool or hair), apparently with a notion of "pulling roughly" (cognates: Greek pekein "to comb, shear," pekos "fleece, wool;" Persian pashm "wool, down," Latin pectere "to comb," Sanskrit paksman- "eyebrows, hair").

Spelling substitution of -gh- for a "hard H" sound was a Middle English scribal habit, especially before -t-. In some late Old English examples, the middle consonant was represented by a yogh. To fight back "resist" is recorded from 1890.
fight (n.) Look up fight at Dictionary.com
Old English feohte, gefeoht "a fight;" see fight (v.). Compare Old Frisian fiucht, Old Saxon fehta, Dutch gevecht, Old High German gifeht, German Gefecht.
fighter (n.) Look up fighter at Dictionary.com
Old English feohtere; agent noun from fight (v.). Compare German Fechter. Meaning "fast military airplane used for combat" is from 1917.
fighting (adj.) Look up fighting at Dictionary.com
present participle adjective from fight (v.). Fighting chance is from 1877; fighting mad is attested by 1750.
figment (n.) Look up figment at Dictionary.com
early 15c., from Latin figmentum "something formed or fashioned, creation," related to figura "shape" (see figure (n.)).
figurative (adj.) Look up figurative at Dictionary.com
late 14c., from Old French figuratif "metaphorical," from Late Latin figurativus, from figurat-, past participle stem of figurare "to form, shape," from figura "a shape, form, figure" (see figure (n.)). Of speech, language, etc., "involving figures of speech," from 1845. Related: Figuratively.
figure (v.) Look up figure at Dictionary.com
late 14c., "to represent" (in a picture); see figure (n.). Meaning "to shape into" is early 15c.; "to picture in the mind" is from c.1600; "to make an appearance" is c.1600. Meaning "work out a sum" is from 1833, American English. Related: Figured; figuring.
figure (n.) Look up figure at Dictionary.com
c.1200, "numeral;" mid-13c. as "visible appearance of a person;" late 14c. as "form of anything," from Old French figure (10c.) "shape, body, form, figure; symbol, allegory," from Latin figura "a shape, form, figure," from PIE *dheigh- "to form, build" (see dough).

Philosophical and scientific senses are from Latin figura being used to translate Greek skhema. The rhetorical use of figure dates to late 14c.; hence figure of speech (1824). Figure eight as a shape was originally figure of eight (c.1600).
figurehead (n.) Look up figurehead at Dictionary.com
1765, from figure (n.) + head (n.). Originally the ornament on the bow of a ship; sense of "leader without real authority" is first attested 1883.
figurine (n.) Look up figurine at Dictionary.com
1854, from French figurine (16c.), from Italian figurina, diminutive of figura, from Latin figura (see figure (n.)).
filament (n.) Look up filament at Dictionary.com
1590s, from Modern Latin filamentum, from Late Latin filare "to spin, draw out in a long line," from Latin filum "thread" (see file (v.)).
filbert (n.) Look up filbert at Dictionary.com
"hazelnut," late 14c., from Anglo-French philber (late 13c.), from Norman dialect noix de filbert, in reference to St. Philbert, 7c. Frankish abbot, so called because the hazel nuts ripen near his feast day, Aug. 22 (Old Style). Weekley compares German Lambertsnuss "filbert," associated with St. Lambert (Sept. 17); also German Johannisbeere "red currant," associated with St. John's Day (June 24). The name is Old High German Filu-berht, literally "very bright."
filch (v.) Look up filch at Dictionary.com
"steal," 1560s, slang, perhaps from c.1300 filchen "to snatch, take as booty," of unknown origin. Liberman says filch is probably from German filzen "comb through." Related: Filched; filching.
filcher (n.) Look up filcher at Dictionary.com
1570s, agent noun from filch.
file (v.) Look up file at Dictionary.com
"to place (papers) in consecutive order for future reference," mid-15c., from Middle French filer "string documents on a wire for preservation or reference," from fil "thread, string" (12c.), from Latin filum "a thread, string," from PIE *gwhis-lom (cognates: Armenian jil "sinew, string, line," Lithuanian gysla "vein, sinew," Old Church Slavonic zila "vein"), from root *gwhi- "thread, tendon." The notion is of documents hung up on a line.
File (filacium) is a threed or wyer, whereon writs, or other exhibits in courts, are fastened for the better keeping of them. [Cowel, "The Interpreter," 1607]
Methods have become more sophisticated, but the word has stuck. Related: Filed; filing.
file (n.2) Look up file at Dictionary.com
metal tool, Old English feol (Mercian fil), from Proto-Germanic *finkhlo (cognates: Old Saxon and Old High German fila, Middle Dutch vile, Dutch vijl, German Feile), probably from PIE *peig- (1) "to cut, mark by incision" (see paint (v.)). The verb in this sense is from early 13c., from Old English filian. Related: Filed; filing.
file (n.1) Look up file at Dictionary.com
1520s, "string or wire on which documents are strung," from French file "row," from Middle French filer (see file (v.)). The meaning "arranged collection of papers" is from 1620s; computer sense is from 1954. The military sense "line or row of men" (1590s) is from the French verb in the sense of "spin out (thread); march in file."
filet (n.) Look up filet at Dictionary.com
1841 in cookery, reborrowing from French of the same word that had been taken 14c. and anglicized as fillet (q.v.). Filet mignon is attested as a French word in English from 1815.
The 'Chateaubriand,' the 'entrecôte,' and the 'filet mignon' (of mutton), with other forms, are all due to the more enlarged sympathies of the French butcher for what is perfect. We must entirely change the mode of cutting up the carcase before we can arrive at the same perfection in form of meat purchasable, and as that is hopeless, so is it useless to insist further on the subject on behalf of the public. ["The Kitchen and the Cellar," "Quarterly Review," April 1877]
filial (adj.) Look up filial at Dictionary.com
late 14c., from Middle French filial, from Late Latin filialis "of a son or daughter," from Latin filius "son," filia "daughter," possibly from a suffixed form of PIE root *bheue- "to be, exist, grow" (see be), though *dhe(i)- "to suck, suckle" (see fecund) "is more likely" [Watkins].
filiation (n.) Look up filiation at Dictionary.com
1520s, from French filiation, from Medieval Latin filiationem (nominative filiatio), noun of action from filiare "to have a child," from Latin filius/filia (see filial).
filibuster (n.) Look up filibuster at Dictionary.com
1580s, flibutor "pirate," probably ultimately from Dutch vrijbuiter "freebooter," a word which used of pirates in the West Indies in Spanish (filibustero) and French (flibustier) forms, either or both of which gave the word to American English (see freebooter).

Used 1850s and '60s of lawless adventurers from the U.S. who tried to overthrow Central American governments. The legislative sense is not in Bartlett (1859) and seems not to have been in use in U.S. legislative writing before 1865. Probably the extension in sense is because obstructionist legislators "pirated" debate or overthrew the usual order of authority. Not technically restricted to U.S. Senate, but that's where the strategy works best.
filibuster (v.) Look up filibuster at Dictionary.com
1853 in both the freebooting and the legislative senses, from filibuster (n.). Related: Filibustered; filibustering.
filicide (n.) Look up filicide at Dictionary.com
1660s, "action of killing a son or daughter," from Latin filius/filia "son/daughter" (see filial) + -cide. Meaning "one who kills a son or daughter" is from 1823. Related: Filicidal.
filigree (n.) Look up filigree at Dictionary.com
1690s, shortening of filigreen (1660s), from French filigrane "filigree" (17c.), from Italian filigrana, from Latin filum "thread" (see file (v.)) + granum "grain" (see corn (n.1)). Related: Filigreed.
Filipino (n.) Look up Filipino at Dictionary.com
1898 (fem. Filipina), Spanish, from las Islas Filipinas "the Philippine Islands" (see Philippines).
fill (v.) Look up fill at Dictionary.com
Old English fyllan "fill up, replenish, satisfy," from Proto-Germanic *fullijan (cognates: Old Saxon fulljan, Old Norse fylla, Old Frisian fella, Dutch vullen, German füllen "to fill"), a derivative of adj. *fullaz "full" (see full (adj.)). Related: Filled.

To fill the bill (1882) originally was U.S. theatrical slang, in reference to a star whose name would be the only one on a show's poster. To fill out "write in required matter" is recorded from 1880. Fill-in "substitute" (n.) is from 1918.
fill (n.) Look up fill at Dictionary.com
"a full supply," mid-13c., fille, from Old English fylle, from Proto-Germanic *fullin- (cognates: Old High German fulli, German Fülle, Old Norse fyllr), noun of state from *fullaz "full" (see full (adj.)). Meaning "extra material in music" is from 1934.
filler (n.) Look up filler at Dictionary.com
late 15c., "one who fills," agent noun from fill (v.). Meaning "something used to fill" is from 1590s. Specifically of food products by 1901.
fillet (n.) Look up fillet at Dictionary.com
early 14c., "headband," from Old French filet (12c.) "thread, filament; strip, ligament," diminutive of fil "thread" (see file (v.)). Sense of "cut of meat or fish" is from late 14c., apparently so called because it was prepared by being tied up with a string. As a verb, from c.1600, "to bind with a narrow band;" meaning "to cut in fillets" is from 1846. Related: Filleted; filleting.
filling (n.) Look up filling at Dictionary.com
verbal noun from fill (v.). Dentistry sense is from 1848. Filling station attested by 1921.
fillip (v.) Look up fillip at Dictionary.com
mid-15c., philippen "to flip something with the fingers, snap the fingers," possibly of imitative origin. As a noun, from 1520s, fyllippe.
filly (n.) Look up filly at Dictionary.com
c.1400, fyly, possibly from Old Norse fylja, fem. of foli "foal" (see foal (n.)). Slang sense of "young girl" is from 1610s.
film (n.) Look up film at Dictionary.com
Old English filmen "membrane, thin skin," from West Germanic *filminjan (cognates: Old Frisian filmene "skin," Old English fell "hide"), extended from Proto-Germanic *fello(m) "animal hide," from PIE *pel- (4) "skin, hide" (cognates: Greek pella, Latin pellis "skin").

Sense of "a thin coat of something" is 1570s, extended by 1845 to the coating of chemical gel on photographic plates. By 1895 this also meant the coating plus the paper or celluloid. First used of "motion pictures" in 1905.
film (v.) Look up film at Dictionary.com
c.1600, "to cover with a film," from film (v.). Meaning "to make a movie of" is from 1899. Related: Filmed; filming.
film noir (n.) Look up film noir at Dictionary.com
1958, from French, literally "black film," from noir (12c.), from Latin niger (see Negro).
filmmaker (n.) Look up filmmaker at Dictionary.com
from film (n.) + maker.
filmography (n.) Look up filmography at Dictionary.com
1962, from film (n.) + ending from bibliography, etc.
filmstrip (n.) Look up filmstrip at Dictionary.com
1930, from film (n.) + strip (n.).
filmy (adj.) Look up filmy at Dictionary.com
c.1600, from film (n.) + -y (2). Related: Filminess.
filoque Look up filoque at Dictionary.com
Latin, "and from the son" (see filial). "Clause in Nicene Creed which separates Eastern Church from Western" [Weekley].
filter (n.) Look up filter at Dictionary.com
early 15c., from Old French filtre and directly from Medieval Latin filtrum "felt," which was used to strain impurities from liquid, from West Germanic *filtiz (see felt (n.)). Of cigarettes, from 1908.
filter (v.) Look up filter at Dictionary.com
1570s, from Medieval Latin filtrare, from filtrum (see filter (n.)). The figurative sense is from 1830. Related: Filtered; filtering.
filth (n.) Look up filth at Dictionary.com
Old English fylð "uncleanness, impurity," from Proto-Germanic *fulitho (cognates: Old Saxon fulitha "foulness, filth," Dutch vuilte, Old High German fulida), noun derivative of *fulo- "foul" (see foul (adj.)). A classic case of i-mutation.
filthy (adj.) Look up filthy at Dictionary.com
late 12c., fulthe, "corrupt, sinful," from filth + -y (2). Meaning "physically unclean" is from late 14c. Meaning "morally dirty, obscene" is from 1530s.
In early use often hardly more emphatic than the mod. dirty; it is now a violent expression of disgust, seldom employed in polite colloquial speech. [OED]
Related: Filthiness.
filtrate (v.) Look up filtrate at Dictionary.com
1610s, probably a back-formation from filtration. As a noun, from 1846.
filtration (n.) Look up filtration at Dictionary.com
c.1600, perhaps from French filtration (1570s), noun of action from filter "to filter" (see filter (v.)).