Online Etymology Dictionary

ferhoodle (v.): "to confuse, perplex," by 1956, 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 or directly from Medieval Latin ferialis, from Latin feriae "holidays," during which work and business were suspended and devotions were made (see feast (n.)).
ferine (adj.): "wild, in a state of nature," 1630s, from Latin ferinus "pertaining to wild animals," from fera "a wild beast, wild animal" (see fierce).
Feringhee (n.): name used in India for "European; Englishman; Portuguese," 1630s, from Persian Farangi, from Arabic Faranji (10c.), from Old French Franc "Frank" (see Frank) + Arabic ethnic suffix -i. The fr- sound is impossible in Arabic.
fermata (n.): 1876, musical term indicating a pause or hold, Italian, literally "a stop, a pause," from fermare "to fasten, to stop," from fermo "strong, fastened," from Latin firmus "strong; stable" (see firm (adj.)).
ferment (v.): late 14c. (intransitive), from Old French fermenter (13c.) and directly from Latin fermentare "to leaven, cause to rise or ferment," from fermentum "substance causing fermentation, leaven, drink made of fermented barley," perhaps contracted from *fervimentum, from root of fervere "to boil, seethe" (see brew (v.)). Transitive use from 1670s. Figurative use from 1650s. Related: Fermented; fermenting.
ferment (n.): early 15c., from Middle French ferment (14c.), from Latin fermentum "leaven, yeast; drink made of fermented barley;" figuratively "anger, passion" (see ferment (v.)). Figurative sense of "anger, passion, commotion" in English 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 past participle stem of Latin fermentare "to ferment" (see ferment (v.)). Figurative use attested from 1650s.
fermium (n.): radioactive element, 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). With metallic element ending -ium.
fern (n.): Old English fearn "fern," from Proto-Germanic *farno- (source also of Old Saxon farn, Middle Dutch vaern, Dutch varen, Old High German farn, German Farn). Watkins and other sources propose an etymology on the notion of "having feathery fronds" from a possible PIE *por-no- "feather, wing" (source also of Sanskrit parnam "feather;" Lithuanian papartis "fern;" Russian paporot'; Greek pteris "fern"), a proposed suffixed form of the root *per- (2) "to lead, pass over" on the notion of "that which carries a bird in flight" (see port (n.1)).

The plant's ability to appear as if from nothing accounts for the ancient belief that fern seeds conferred invisibility (1590s). Filicology "science or study of ferns" (1848) is from Latin filix "fern."
fern-tickles (n.): "freckles, spots or blemishes on the body" (late 14c.), of unknown origin. Related: Fern-tickled "having spots or blemishes on the skin."
ferocious (adj.): 1640s, from Latin ferocis, oblique case of ferox "fierce, wild-looking" (see ferocity). Alternative ferocient (1650s) is seldom seen. Related: Ferociously; ferociousness.
ferocity (n.): c. 1600, from French férocité, from Latin ferocitatem (nominative ferocitas) "fierceness," from ferocis, oblique case of ferox "bold, courageous, warlike; fierce, savage, headstrong, cruel," 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;" see eye (n.)).
ferret (n.): late 14c., from Old French furet "ferret," diminutive of fuiron "weasel, ferret," literally "thief" (in allusion to the animal's slyness and craftiness), probably from Late Latin furionem (related to furonem "cat," which also meant "robber"), from Latin fur (genitive furis) "thief," probably from PIE *bhor- (which likely also is the source of furtive), from root *bher- (1) "to bear, carry" (see infer). Also from the French word are Dutch fret, German Frett. Ferret-faced is from 1837 (to have ferret-eyes is from 1580s).
ferret (v.): early 15c., "hunt with a ferret," from ferret (n.) or from Old French verb fureter, in reference to the use of half-tame ferrets to kill rats and flush rabbits from burrows. The extended sense of "search out, discover," especially by perseverence and cunning, usually with out (adv.), is from 1570s. Related: Ferreted; ferreting.
ferric (adj.): 1799, "pertaining to or extracted from iron," from Latin ferrum "iron" (see ferro-) + -ic. Especially of iron 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 in 1893. It was 250 feet tall and meant to rival the Eiffel Tower, from the 1889 Paris Exposition. The surname is said to be a 16c. form of Ferrers, borne in England by two families, from two places named Ferrières in Normandy.
ferrite (n.): "compound of ferric oxide and another metallic oxide," 1851, from Latin ferrum "iron" (see ferro-) + -ite (2).
ferro-: before vowels ferr-, word-forming element indicating the presence of or derivation from iron, from Latin ferro-, comb. form of ferrum "iron," which is of unknown origin. Possibly of Semitic origin, via Etruscan [Klein]; Watkins suggests "possibly borrowed (via Etruscan) from the same obscure source as OE bræs "brass." Also sometimes especially indicative of the presence of iron in the ferrous state; ferri- indicating iron in the ferric state.
ferromagnetic (adj.): "behaving like iron in a magnetic field," 1840, from ferro- "iron" + magnetic.
ferrous (adj.): "pertaining to or containing iron," 1865, from Latin ferreus "made of iron," from ferrum "iron" (see ferro-). In chemistry, "containing iron," especially with a valence of two. Contrasted with ferric.
ferrule (n.): "metal cap on a rod," 1610s, ferule, earlier verrel (early 15c.), from Old French virelle "ferrule, collar" (12c. Modern French virole), from Medieval Latin viriola "bracelet," diminutive of Latin viriae "bracelets," from a Gaulish word akin to Old Irish fiar "bent, crooked," from PIE *wi-ria-, from root *wei- (1) "to turn, twist" (see wire (n.)). Spelling influenced by Latin ferrum "iron."
ferry (v.): Old English ferian "to carry, convey, bring, transport" (in late Old English, especially over water), from Proto-Germanic *farjan "to ferry" (source also of Old Frisian feria "carry, transport," Old Norse ferja "to pass over, to ferry," Gothic farjan "travel by boat"), from PIE root *per- (2) "to lead, pass over" (see port (n.1)). Related to fare (v.). Related: Ferried; ferries; ferrying.
ferry (n.): early 15c., "a passage over a river," from the verb or from Old Norse ferju-, in compounds, "passage across water," ultimately from the same Germanic root as ferry (v.). Meaning "place where boats pass over a body of water" is from mid-15c. The sense "boat or raft to convey passengers and goods short distances across a body of water" (1580s) is a shortening of ferry boat (mid-15c.).
fertile (adj.): mid-15c., "bearing or producing abundantly," from Middle French fertil (15c.) and directly from Latin fertilis "bearing in abundance, fruitful, productive," from ferre "to bear" (see infer). Fertile Crescent (1914) was coined by U.S. archaeologist James H. Breasted (1865-1935) of University of Chicago in "Outlines of European History," Part I.
fertilisation (n.): chiefly British English spelling of fertilization. For spelling, see -ize.
fertility (n.): early 15c., from Middle French fertilité, from Latin fertilitatem (nominative fertilitas) "fruitfulness, fertility," from fertilis "fruitful, productive" (see fertile).
fertilization (n.): 1857, noun of action from fertilize, or else from French fertilisation.
fertilize (v.): 1640s, "make fertile;" see fertile + -ize. Its biological sense of "unite with an egg cell" is first recorded 1859. Related: Fertilized; fertilizing.
fertilizer (n.): 1660s, "something that fertilizes (land)," agent noun from fertilize. As a euphemism for "manure," from 1846.
ferule (n.): "rod or flat piece of wood for punishing children," 1590s, earlier "giant fennel" (early 15c.), from Middle English ferula "fennel plant" (late 14c.), from Latin ferula "reed, whip, rod, staff; fennel plant or stalk" (fennel stalks were used for administering flogging punishment in ancient Roman times) probably related to festuca "stalk, straw, rod."
fervent (adj.): mid-14c., from Old French fervent "fervent, ardent" (12c.), from Latin ferventem (nominative fervens) "boiling, hot, glowing," figuratively "violent, impetuous, furious," present participle of fervere "to boil, glow," from PIE root *bhreuə- "to boil, bubble" (see brew (v.)). The figurative sense of "impassioned" is first attested c. 1400. Related: Fervency; fervently.
fervid (adj.): 1590s, "burning, glowing, hot," from Latin fervidus "glowing, burning; vehement, fervid," from fervere "to boil, glow" (see brew (v.)). Figurative sense of "impassioned" is from 1650s. Related: Fervidly; fervidness.
fervor (n.): mid-14c., "warmth or glow of feeling," from Old French fervor "heat; enthusiasm, ardor, passion" (12c., Modern French ferveur), from Latin fervor "a boiling, violent heat; passion, ardor, fury," from fervere "to boil; be hot" (see brew (v.)).
fervour (n.): chiefly British English spelling of fervor (q.v.); for spelling, see -or.
Fescennine (adj.): "vulgar, obscene, scurrilous," from Latin Fescenninus (versus), a rude form of dramatic or satiric verse, from Fescennia, city in Etruria, noted for such productions.
The Fescennine Songs were the origin of the Satire, the only important species of literature not derived from the Greeks, and altogether peculiar to Italy. These Fescennine Songs were rude dialogues, in which the country people assailed and ridiculed one another in extempore verses, and which were introduced as an amusement in various festivals. [William Smith, "A Smaller History of Rome," London, 1870]
fescue (n.): 1510s, "teacher's pointer," alteration of festu "piece of straw, twig" (late 14c.), from Old French festu "straw; object of little value" (12c., Modern French fétu), from Vulgar Latin festucum, from Latin festuca "straw, stalk, rod," probably related to ferula "reed, whip, rod" (see ferule). Sense of "pasture, lawn grass" is first recorded 1762. Wyclif (1382) has festu in Matt. vii:3 for the "mote" in the eye. In Old French rompre le festu was to symbolically break a straw to signify the breaking of a bond.
fess (n.): wide horizontal band across an escutcheon, late 15c., from Old French faisce, from Latin fascia "a band" (see fasces).
fess (v.): shortened form of confess, attested by 1840, American English. With up (adv.) from 1930. Related: Fessed; fesses; fessing.
fest (n.): see -fest.
festal (adj.): late 15c., from Old French festal, from Late Latin festalis, from Latin festum "feast" (see feast (n.)).
fester (v.): late 14c., of wounds, "to become ulcerous, suppurate," from festre (n.) "a fistula" (c. 1300), or from Old French verb festrir "ulcerate, fester," from festre (n.) "small sore discharging pus." The nouns in Old French and Middle English both are from Latin fistula "pipe, ulcer" (see fistula). Related: Festered; festering; festerment.
festival (n.): 1580s, "a festal day, appointed day of festive celebration," short for festival day (late 14c.), from Old French festival (adj.) "suitable for a feast; solemn, magnificent, joyful, happy," and directly from Medieval Latin festivalis "of a church holiday," from festum "festival, holiday" (see festivity). The English word returned to French 19c. in certain specialized senses.
festive (adj.): 1650s, "pertaining to a feast," from Latin festivus "festive, joyous, gay," from festum "festival, holiday," noun use of neuter of adjective festus (see feast (n.)). The word is unattested in English from 1651 to 1735 (it reappears in a poem by William Somervile, with the sense "fond of feasting, jovial"), and the modern use may be a back-formation from festivity. Meaning "mirthful, joyous" in English is attested by 1774. Related: Festively; festiveness.
When the Day crown'd with rural, chaste Delight
Resigns obsequious to the festive Night;
The festive Night awakes th' harmonious Lay,
And in sweet Verse recounts the Triumphs of the Day.

[Somervile, "The Chace"]
Earlier adjectives in English based on the Latin word were festival "pertaining to a church feast" (late 14c.); festful "joyous" (early 15c.), festial "pertaining to a church feast" (early 15c.), festli "fond of festivity" (late 14c.).
festivity (n.): "festive celebration, feast," late 14c., from Old French festiveté "celebration, festiveness, festival," from Latin festivitatem (nominative festivitas) "good fellowship, generosity," from festivus "festive," from festum "festival or holiday," neuter of festus "of a feast" (see feast (n.)). Related: Festivities.
festoon (n.): "string or chain of flowers, ribbon, or other material suspended between two points," 1620s, from French feston (16c.), from Italian festone, literally "a festive ornament," apparently from festa "celebration, feast," from Vulgar Latin *festa (see feast (n.)). The verb is attested from 1789. Related: Festooned.
festschrift (n.): "volume of writings by various scholars presented as a tribute or memorial to a veteran scholar," 1898, from German Festschrift, literally "festival writing" (see -fest + script (n.)).
festucine (adj.): "straw-colored," 1640s, from Latin festuca "straw" (see fescue).
Festus: masc. proper name, from Latin, literally "solemn, joyous, festive" (see feast (n.)).