Online Etymology Dictionary

fem (n.): slang for "woman," by 1936, from female.
female (n.): early 14c., from Old French femelle (12c.) "woman, female," from Medieval Latin femella "a female," from Latin femella "young female, girl," diminutive of femina "woman" (see feminine).

Sense extended in Vulgar Latin from humans to female of other animals. Spelling altered late 14c. on mistaken parallel of male. As an adjective, from early 14c. Reference to sockets, etc., is from 1660s.
femaleness (n.): 1889, from female + -ness.
feme covert (n.): "married woman" (legalese), c.1600, French, from Old French feme coverte, second element fem. of covert "covered." Contrasted to feme sole.
feminine (adj.): mid-14c., "of the female sex," from Old French femenin (12c.) "feminine, female; with feminine qualities, effeminate," from Latin femininus "feminine" (in the grammatical sense at first), from femina "woman, female," literally "she who suckles," from root of felare "to suck, suckle" (see fecund). Sense of "woman-like, proper to or characteristic of women" is recorded from mid-15c.

The interplay of meanings now represented in female, feminine, and effeminate, and the attempt to make them clear and separate, has led to many coinages: feminitude (1878); feminile "feminine" (1640s); feminility "womanliness" (1838); femality (17c., "effeminacy;" 1754 "female nature"). Also feminality (1640s, "quality or state of being female"), from rare adjective feminal (late 14c.), from Old French feminal. And femineity "quality or state of being feminine," from Latin femineus "of a woman, pertaining to a woman."
femininity (n.): late 14c., femynynytee, from feminine + -ity.
feminism (n.): 1851, "state of being feminine;" sense of "advocacy of women's rights" is 1895, from French féminisme (1837); see feminine + -ism.
feminist (n.): 1893, from French féministe (1872); cf. feminism. As an adjective by 1897. Womanist sometimes was tried as a native alternative.
feminity (n.): "quality or state of being feminine," late 14c., from Old French feminité, from Latin femina (see feminine).
feminization (n.): 1844, noun of action from feminize.
feminize (v.): 1650s, from Latin femina (see feminine) + -ize. Related: Feminized; feminizing. Femalize (1670s, intransitive, 1709, transitive) and femininize (1868) are more rare.
femme (n.): French, literally "woman," from Old French feme, from Latin femina (see feminine). Slang meaning "passive and more feminine partner in a lesbian couple" attested by 1961.
femme fatale (n.): "attractive and dangerous woman," 1895, from French femme fatale, attested by 1844, from French femme "woman," from Latin femina (see feminine) + fatale (see fatal).
Une femme fatale est une femme qui porte malheur. [Jules Claretie, "La Vie a Paris," 1896]
Earlier, such a woman might be called a Circe.
femoral (adj.): 1782, from Latin femoris, genitive of femur "thigh" (see femur) + -al (1).
femur (n.): 1560s, from Latin femur "thigh," of unknown origin; borrowed first as an architectural term, 1799 as "thighbone."
fen (n.): Old English fenn "mud, mire, dirt; fen, marsh, moor," from Proto-Germanic *fanjam- (cf. Old Saxon feni, Old Frisian fenne, Middle Dutch venne, Dutch veen, Old High German fenna, German Fenn "marsh," Old Norse fen, Gothic fani "mud"), from PIE *pen- "swamp" (cf. Gaulish anam "water," Sanskrit pankah "bog, marsh, mud," Old Prussian pannean "swampland"). Italian and Spanish fango, Old French fanc, French fange "mud" are loan-words from Germanic. The native Latin word was limus or lutum.
fence (n.): early 14c., "action of defending," shortening of defens (see defense). Spelling alternated between -c- and -s- in Middle English. Sense of "enclosure" is first recorded mid-15c. on notion of "that which serves as a defense." Sense of "dealer in stolen goods" is thieves' slang, first attested c.1700, from notion of such transactions taking place under defense of secrecy. To be figuratively on the fence "uncommitted" is from 1828, from the notion of spectators at a fight.
fence (v.): mid-15c., "surround with a fence;" c.1500, "defend, screen, protect;" 1590s, "fight with swords;" the last from the noun in this sense (1530s); see fence (n.). Related: Fenced, fencing.
fencible (adj.): early 14c., "capable of making a defense," short for defensible; see fence (n.) + -ible.
fencing (n.): mid-15c., "defending, act of protecting;" 1580s in the sword-fighting sense; noun from present participle of fence (v.). In spite of the re-enactment in 1285 of the Assize of Arms of 1181, fencing was regarded as unlawful in England. The keeping of fencing schools was forbidden in the City of London, "as fools who delight in mischief do learn to fence with buckler, and thereby are encouraged in their follies." Meaning "putting up fences" is from 1620s; that of "an enclosure" is from 1580s; meaning "receiving stolen goods" is from 1851 (see fence (n.)); meaning "materials for an enclosure" is from 1856.
fend (v.): late 13c., shortening of defend. To fend for oneself (1620s) is to see to one's own defense. Related: Fended; fending.
fender (n.): late 13c., shortening of defender. Used of attachments to boats at first, of fireplaces since 1680s; application to automobiles is 1919.
fenestration (n.): 1870 in the anatomical sense, noun of action from Latin fenestrare, from fenestra "window, opening for light," perhaps from Etruscan. Meaning "arrangement of windows" is from 1846. Related: Fenestrated.
feng shui (n.): also feng-shui, 1797, from Chinese, from feng "wind" + shui "water." A system of spiritual influences in natural landscapes and a means of regulating them.
Fenian: 1816, blend of Old Irish feinne, plural of fiann, name of a band of Irish warriors + Old Irish Fene, name of the ancient inhabitants of Ireland. Reference to Irish-American brotherhood of that name first attested 1864.
fennec (n.): fox-like animal of Africa, 1790, from Arabic fenek, fanak "a name vaguely applied to various fur-bearing animals" [OED].
fennel (n.): Old English fenol, finul, perhaps via (or influenced by) Old French fenoil or directly from Vulgar Latin fenuculum, from Latin feniculum, diminutive of fenum, faenum "hay," probably literally "produce" (see fecund). Apparently so called from its hay-like appearance and sweet odor.
fenugreek (n.): Old English fenograecum, from Latin faenugraecum, literally "Greek hay," from faenum (see fennel) + Graecum. The modern form in English is from Middle French fenugrec.
fer de lance (n.): large poisonous snake of American tropics, 1880, from French, "lance-head," literally "iron of a lance." So called for its shape.
feral (adj.): c.1600, from Middle French feral "wild," from Latin fera, in phrase fera bestia "wild animal," from ferus "wild" (see fierce).
Ferdinand: masc. proper name, of Germanic origin, first element perhaps Proto-Germanic *farthi, abstract noun from root *far- "to fare, travel" (see fare (v.)); second element perhaps related to Old English neðan, Old High German nendan "to risk, venture."
fere (n.): "companion" (obsolete), from Middle English fere, a shortening of Old English gefera "associate, comrade, fellow-disciple; wife, man, servant," from root of faran "to go, travel" (cf. German Gefährte "companion;" see fare (v.)).
Fergus: masc. proper name, from Gaelic Fearghus or Old Irish Fergus "man-ability," first element cognate with Latin vir "man," second from Old Irish gus "ability, excellence, strength, inclination," from Celtic root *gustu- "choice," from PIE root *geus- "to taste" (see gusto).
ferhoodle (v.): "to confuse, perplex," from Pennsylvania German verhuddle "to confuse, tangle," related to German verhudeln "to bungle, botch." Related: Ferhoodled; ferhoodling.
ferial (adj.): "pertaining to holidays," late 14c., from Old French ferial, from Medieval Latin ferialis, from Latin feriae (see feast (n.)).
ferine (adj.): 1630s, from Latin ferinus "pertaining to wild animals," from fera "wild beast" (see fierce).
Feringhee (n.): name used in India for "European," 1630s, from Persian Farangi, from Arabic Faranji (10c.), from Old French Franc "Frank" (see Frank) + Arabic ethnic suffix -i. The fr- sound is not possible in Arabic.
fermata (n.): 1876, musical term, Italian, literally "stop, pause," from fermare "to fasten, to stop," from fermo "strong, fastened," from Latin firmus (see firm (adj.)).
ferment (v.): late 14c., from Old French fermenter (13c.) and directly from Latin fermentare "to leaven, ferment," from fermentum "substance causing fermentation, leaven," from root of fervere "to boil, seethe" (see brew). Figurative use from 1650s. Related: Fermented; fermenting.
ferment (n.): early 15c., from Middle French ferment, from Latin fermentum (see ferment (v.)). Figurative sense of "anger, passion" is from 1670s.
fermentation (n.): late 14c., in alchemy, with a broad sense; modern scientific sense is from c.1600; from Late Latin fermentationem (nominative fermentatio), noun of action from fermentare (see ferment (v.)). Figurative use attested from 1650s.
Fermium (n.): discovered in the debris of a 1952 U.S. nuclear test in the Pacific, named 1955 for Italian-born U.S. physicist Enrico Fermi (1901-1954).
fern (n.): Old English fearn, from Proto-Germanic *farno- (cf. Old Saxon farn, Middle Dutch vaern, Dutch varen, Old High German farn, German Farn), possibly with a sense of "having feathery fronds" and from PIE *por-no-, a root which has yielded words for "feather, wing" (cf. Sanskrit parnam "feather;" Lithuanian papartis "fern;" Russian paporot'; Greek pteris "fern," pteron "feather"), from root *per- (see petition (n.)). The plant's ability to appear as if from nothing accounts for the ancient belief that fern seeds conferred invisibility.
ferocious (adj.): 1640s, from Latin ferocis, oblique case of ferox "fierce, wild-looking" (see ferocity). Related: Ferociously; ferociousness.
ferocity (n.): c.1600, from French férocité, from Latin ferocitatem (nominative ferocitas) "fierceness," from ferocis, oblique case of ferox "wild, bold, courageous, warlike, fierce," literally "wild-looking," a derivative of ferus "wild" (see fierce) + -ox, -ocem (genitive -ocis), a suffix meaning "looking or appearing" (cognate with Greek ops "eye, sight").
ferret (v.): early 15c., from ferret (n.), in reference to the use of half-tame ferrets to kill rats and flush rabbits from burrows; the extended sense of "search out, discover" is 1570s. Related: Ferreted; ferreting.
ferret (n.): late 14c., from Old French furet, diminutive of fuiron "weasel, ferret," literally "thief," probably from Late Latin furionem (related to furonem "cat," also "robber"), from Latin fur (genitive furis) "thief."
ferric (adj.): 1799, from Latin ferrum "iron" (see ferro-) + -ic. Of iron, especially with a valence of three.
ferrier (n.): "ferryman," mid-15c., from ferry + -er (1).
Ferris wheel (n.): 1893, American English, from U.S. engineer George W.G. Ferris (1859-1896), who designed it for the World's Columbian Exposition, held in Chicago, 1893. It was 250 feet tall and meant to rival the Eiffel Tower, from the 1889 Paris Exposition.