Online Etymology Dictionary

funereal (adj.): "suitable for a funeral" (mournful, dismal, gloomy), 1725, from stem of Latin funereus "of a funeral," from funus "funeral; death" (see funeral) + -al (1). Perhaps by influence of Middle French funerail.
funest (adj.): "portending death," 1650s, obsolete from 18c. except in poetry, from Middle French funeste "unlucky" (14c.), from Latin funestus "causing death, destructive; mournful," from funus "a funeral" (see funeral (n.)). Related: Funestal (1550s).
fungal (adj.): 1835, from Modern Latin fungalis, from fungus (see fungus). As a noun, "a fungus" (1845). Earlier adjective was fungic 1804.
fungi (n.): Latin plural of fungus. In biology, in reference to one of the lowest of the great groups of cellular cryptograms.
fungible (adj.): "capable of being used in place of another; capable of being replaced," 1818, a word in law originally, from Medieval Latin fungibilis, from Latin fungi "perform" (see function (n.)) via phrases such as fungi vice "to take the place." Earlier as a noun (1765).
fungicide (n.): 1889; see fungus + -cide. Related: Fungicidal.
fungiform (adj.): "mushroom-shaped," 1801, from stem of fungus + -form.
fungivorous (adj.): 1826, from stem of fungus + -vorous.
fungo (n.): "A fly ball hit to a player during fielding practice in which the batter (often a coach) tosses the ball into the air and hits it as it descends with a long and narrow bat." [Paul Dickson, "The Dickson Baseball Dictionary," 3rd ed., 2009], attested from 1867 (fungoes), baseball slang, of unknown origin; see Dickson's book for a listing of the guesses. Perhaps from a Scottish fung "to pitch, toss, fling;" perhaps from some dialectal fonge "catch," a relic of Old English fon "seize" (see fang), or possibly from the German cognate fangen. Not in OED 2nd ed. (1989). There does not seem to have been a noun phrase (a) fun go in use at the time. It formally resembles the Spanish and Italian words for "fungus."
fungous (adj.): mid-15c., "spongy, tender," from Latin fungosus "full of holes, spongy," from fungus "a mushroom, fungus" (see fungus). Meaning "pertaining to or characterized by fungus" is from 18c.; figuratively, often "springing up suddenly" (1751).
fungus (n.): 1520s, "a mushroom," from Latin fungus "a mushroom, fungus;" used in English at first as a learned alternative to mushroom (funge was used in this sense late 14c.). The Latin word is believed to be cognate with (or derived from) Greek sphongos, the Attic form of spongos "sponge" (see sponge (n.)). "Probably a loanword from a non-IE language, borrowed independently into Greek, Latin and Armenian in a form *sphong- ...." [de Vaan]
funicular (adj.): 1660s, from funicle "a small cord" (1660s), from Latin funiculus "a slender rope," diminutive of funis "a cord, rope," of unknown etymology. De Vaan suggests it is a derivative of the root of filum. A funicular railway (1874) is one worked by a cable from a stationary engine.
funipendulous (adj.): "hanging from a rope," 1706, from stem of Latin funis "a cord, rope" + pendulus (see pendulous) + -ous.
funk (n.1): "depression, ill-humor," perhaps from earlier sense "cowering state of fear" (1743), identified in OED as originally Oxford slang, probably from Scottish and Northern English verb funk "become afraid, shrink through fear, fail through panic," (1737), of unknown origin. Perhaps from Flemish fonck "perturbation, agitation, distress," which is possibly related to Old French funicle "wild, mad."
funk (n.2): "bad smell," 1620s, probably from the verb funk in the sense "blow smoke upon; stifle with offensive vapor" (though this is not recorded until later 17c.). It is from dialectal French funkière "to smoke," from Old French fungier "give off smoke; fill with smoke," from Latin fumigare "to smoke" (see fume (n.)).

Not considered to be related to obsolete funk (n.) "a spark," mid-14c., fonke, a general Germanic word (compare Dutch vonk, Old High German funcho, German Funke. The Middle English word is probably from Low German or from an unrecorded Old English form.

In reference to a style of music felt to have a strong, earthy quality, it is attested by 1959, a back-formation from funky (q.v.).
funky (adj.): 1784, "old, musty," in reference to cheeses, then "repulsive," from funk (n.2) + -y (2). It began to develop an approving sense in jazz slang c. 1900, probably on the notion of "earthy, strong, deeply felt." Funky also was used early 20c. by white writers in reference to body odor allegedly peculiar to blacks. The word reached wider popularity c. 1954 (it was defined in "Time" magazine, Nov. 8, 1954) and in the 1960s acquired a broad slang sense of "fine, stylish, excellent."
funnel (n.): c. 1400, funell, fonel, from Middle French fonel, apparently a word from a southern French dialect, such as Provençal enfounilh (Weekley calls it "a word from the Southern wine trade"), from Late Latin fundibulum, shortened from Latin infundibulum "a funnel or hopper in a mill," from infundere "pour in," from in- "in" + fundere "pour" (see found (v.2)).
funnel (v.): 1590s, from funnel (n.). Related: Funneled; funneling.
funnies (n.): "newspaper comic strips," 1852, plural noun formation from funny (adj.).
funnily (adv.): "in an amusing manner, comically," 1814, from funny + -ly (2).
funniment (n.): "drollery, jesting," 1842, jocular formation from funny on model of merriment.
funning (n.): "jesting, joking," by 1900, verbal noun from fun (v.).
funny (adj.): "humorous," 1756, from fun (n.) + -y (2). Meaning "strange, odd, causing perplexity" is by 1806, said to be originally U.S. Southern (marked as colloquial in Century Dictionary). The two senses of the word led to the retort question "funny ha-ha or funny peculiar," which is attested by 1916. Related: Funnier; funniest. Funny farm "mental hospital" is slang from 1962. Funny bone "elbow end of the humerus" (where the ulnar nerve passes relatively unprotected) is from 1826, so called for the tingling sensation when struck. Funny-man was originally (1854) a circus or stage clown.
fur (n.): late 14c. "trimming or lining of a garment" (implied c. 1300 in surname Furhode "fur hood"), probably from Old French forrer, fourrer "cover with fur, line (clothing)," in general "to cover, fill with," from fuerre "sheath, scabbard" (via notion of "covering"), from Frankish *fodr or another Germanic source, from Proto-Germanic *fodram "sheath" (source also of Old Frisian foder "coat lining," Old High German fotar "a lining," German Futter, Gothic fodr "sword sheath"), from PIE root *pa- "to protect, feed" (see food (n.)).

First applied c. 1400 to the hairy pelt of an animal, whether still on the animal or not. The Old French noun might have had the sense "hide, fur, pelt" (and thus might serve as the immediate source of the English noun), but this is not attested. Absent this, the sense transfer from the lining to the material that goes to make it probably happened in English. As an adjective from 1590s.
I'le make the fur Flie 'bout the eares of the old Cur. [Butler, "Hudibras," 1663]
fur (v.): c. 1300 (implied in furred), from fur (n.) or Old French fourrer "to line." Related: Furring.
furbelow (n.): "puffed flounce, plaited border," c. 1700, folk-etymology alteration (as if fur below) of falbala, from French falbala (17c., cognate with Provençal farbello), from Italian falda "fold, flap, pleat," from a Germanic source, from Proto-Germanic *faldan, from PIE *pel- (3) "to fold" (see fold (v.)). As a verb from 1701.
furbish (v.): late 14c. (implied mid-13c. in surname Furbisher), from Old French forbiss-, present participle stem of forbir "to polish, burnish; mend, repair" (12c., Modern French fourbir), from a Germanic source, from Proto-Germanic *furbjan "cause to have a (good) appearance" (compare Old High German furban "to polish"), from PIE *prep- "to appear," which is perhaps identical with *kwrep- "body, appearance" (see corporeal). Related: Furbished; furbishing. The Old English cognate of the Germanic verbs, feormian (with intrusive -m-) meant "clean, rub bright, polish."
furcate (adj.): "forked, branching like the prongs of a fork," 1819, from Medieval Latin furcatus, from Latin furca "a two-pronged fork" (see fork (n.)). As a verb, from 1828 (implied in furcated).
furcation (n.): 1640s, noun of action or state from stem of Medieval Latin furcatus (see furcate (adj.)).
furious (adj.): late 14c., "impetuous, unrestrained," from Old French furios, furieus "furious, enraged, livid" (14c., Modern French furieux), from Latin furiosus "full of rage, mad," from furia "rage, passion, fury" (see fury). Furioso, from the Italian form of the word, was used in English 17c.-18c. for "an enraged person," probably from Ariosto's "Orlando Furioso."
furiously (adv.): 1550s, from furious + -ly (2).
furl (v.): 1550s, of uncertain origin, possibly from Middle French ferler "to furl," from Old French ferliier "chain, tie up, lock away," perhaps from fer "firm" (from Latin firmus; see firm (adj.)) + -lier "to bind" (from Latin ligare). Also said to be a shortening of earlier furdle "to furl or fold." Related: Furled; furling. As a noun from 1640s.
furlong (n.): measure of distance of roughly 660 feet, from Old English furlang, originally the length of a furrow in a common field of 10 acres, from furh "furrow" (see furrow (n.)) + lang "long" (see long (adj.)). The "acre" of the common field being variously measured, the furlong varied but eventually was fixed by custom at 40 rods. Used from 9c. to translate Latin stadium (625 feet), one-eighth of a Roman mile, and so the English word came to be used for "one-eighth of an English mile," though this led to a different measure for the English mile than the Roman one. Furlong being so important in land deed records (where mile hardly figures) it was thought best to redefine the mile rather than the furlong, which was done under Elizabeth I.
furlough (n.): 1620s, vorloffe, from Dutch verlof, literally "permission," from Middle Dutch ver- "completely, for" + laf, lof "permission," from Proto-Germanic *laubo- (see leave (v.)). The -gh spelling predominated from 1770s and represents the "f" that had been pronounced at the end of the word but disappeared fairly soon thereafter in English.
furlough (v.): 1783, "grant leave of absence" (to a soldier), from furlough (n.). Of employees, "lay off or suspend temporarily," by 1940. Related: Furloughed; furloughing.
furnace (n.): early 13c., from Old French fornais "oven, furnace," figuratively "flame of love" (12c.), from Latin fornacem (nominative fornax) "an oven, kiln," related to fornus/furnus "oven," and to formus "warm," from PIE root *gwher- "warm" (source also of Greek thermos, Old English wearm; see warm (adj.)).
furnish (v.): mid-15c., "fit out, equip, to provision" (a castle, ship, person); "provide (soldiers)," from Old French furniss-/forniss-, present participle stem of furnir/fornir "accomplish, carry out; equip, fit out; provide" (12c.), from Vulgar Latin *fornire, alteration of *fromire, from West Germanic *frumjan "forward movement, advancement" (source also of Old High German frumjan "to do, execute, provide"), from Proto-Germanic *fram- "forwards" (see from). General meaning "to provide" (something) is from 1520s; specifically "provide furniture for a room or house" from 1640s. Related: Furnished; furnishing.
furnished (adj.): "equipped," 1550s, past participle adjective from furnish. Of rooms, houses, etc. "provided with furniture," from 1640s.
furnishings (n.): articles of furniture, c. 1600, plural verbal noun from furnish (v.).
furniture (n.): 1520s, "act of supplying or providing," from Middle French fourniture "a supply; act of furnishing," from Old French forneture (13c.), from fornir "to furnish" (see furnish). Sense of "chairs, tables, etc.; household stuff; movables required or ornamental in a dwelling-place" (1570s) is unique to English; most other European languages derive their words for this from Latin mobile "movable."
furor (n.): "rage, madness, angry mania," late 15c., from Middle French fureur (12c.), from Latin furor "a ravaging, rage, madness, passion," which is related to furia "rage, passion, fury" (see fury).
furore (n.): 1790, Italian form of furor, borrowed into English originally in the sense "enthusiastic popular admiration;" it later descended to mean the same thing as furor and lost its usefulness.
furrier (n.): "dealer or dresser in furs," late 13c., as a surname, ffurrere, via Anglo-French from Old French forreor "furrier," from forrer "to line or trim with fur" (see fur (n.)).
furrow (n.): Middle English furwe, forowe, forgh, furch, from Old English furh "furrow, trench in the earth made by a plow," from Proto-Germanic *furkh- (source also of Old Frisian furch "furrow;" Middle Dutch vore, Dutch voor; German Furche "furrow;" Old Norse for "furrow, drainage ditch"), from PIE *perk- (2) "to dig, tear out" (source also of Latin porca "ridge between two furrows," Old Irish -rech, Welsh rhych "furrow"). General meaning "narrow trench or channel" is from early 14c. In reference to a deep wrinkle on the face, by 1580s.
furrow (v.): early 15c., "to plow, make furrows in," from furrow (n.). Meaning "to make wrinkles in one's face, brow, etc." is from 1590s. Old English had furian (v.). Related: Furrowed; furrowing.
furry (adj.): 1670s, "made of fur, covered with fur," from fur + -y (2). As a noun, in reference to "anthropomorphic animal characters with human personalities," also of people who identify with them, by 1995. Related: Furriness; furries.
further (adv.): Old English furðor, forðor "to a more advanced position, forward, onward, beyond, more distant; farther away; later, afterward; to a greater degree or extent, in addition; moreover," etymologically representing either "forth-er" or "fore-ther." The former would be from furðum (see forth) + comparative suffix *-eron-, *-uron- (compare inner, outer).

Alternative etymology (Watkins) traces it to Proto-Germanic *furthera-, from PIE *pr-tero- (source also of Greek proteros "former"), representing the root *per- (1) "forward, through" (see per) + comparative suffix also found in after, other. Senses of "in addition, to a greater extent" are later metaphoric developments.

It replaced or absorbed farrer, ferrer as comparative of far (itself a comparative but no longer felt as one). Farrer itself displaced Old English fierr in this job; farrer survived until 17c., then was reduced to dialect by rival farther. "The primary sense of further, farther is 'more forward, more onward'; but this sense is practically coincident with that of the comparative degree of far, where the latter word refers to real or attributed motion in some particular direction." [OED]
further (v.): Old English fyrðran, fyrðrian "to impel, urge on; advance, promote, benefit;" see further (adv.). Compare Middle Low German vorderen, Old High German furdiran, German fördern, probably from their respective adjectives via the notion in phrases such as Old English don furðor "to promote." Related: Furthered; furthering. After the further/farther split, this sense also continued in a shadow verb farther (v.), attested from 16c. but apparently dying out 19c.
further (adj.): Old English furðra "further, greater, superior," probably a prehistoric derivative of further (adv.). Compare Old Frisian fordera, German vorder "that is before another." In early Middle English it also meant "earlier, former, previous;" a great-grandfather was a furþur ealdefader (12c.), and a previous wife was referred to legally as a forther wife.
furtherance (n.): mid-15c., "assistance, support," also "advantage, benefit; advancement, promotion," from further (v.) + -ance.