fun (n.) Look up fun at Dictionary.com
"diversion, amusement," 1727, earlier "a cheat, trick" (c.1700), from verb fun (1680s) "to cheat, hoax," of uncertain origin, probably a variant of Middle English fonnen "befool" (c.1400; see fond).

Stigmatized by Johnson as "a low cant word." Older sense is preserved in phrase to make fun of (1737) and funny money "counterfeit bills" (1938, though this may be more for the sake of the rhyme). See also funny.
funambulist (n.) Look up funambulist at Dictionary.com
"rope-walker," 1793, coined from Latin funis "rope" + ambulare "to walk" (see amble (v.)).
function (n.) Look up function at Dictionary.com
1530s, "proper work or purpose," from Middle French fonction (16c.) and directly from Latin functionem (nominative functio) "performance, execution," noun of action from functus, past participle of fungi "perform, execute, discharge," from PIE root *bheug- (2) "to use, enjoy" (see brook (v.)). Use in mathematics probably begun by Leibnitz (1692).
function (v.) Look up function at Dictionary.com
1856, from function (n.). Related: Functioned; functioning.
functional (adj.) Look up functional at Dictionary.com
1630s; as a term in architecture, "utilitarian," 1928; see function (n.) + -al (1). Related: Functionally; functionality.
functionalism (n.) Look up functionalism at Dictionary.com
1914 as a term in social sciences; 1930 in architecture; from functional + -ism. Related: functionalist.
functionary (n.) Look up functionary at Dictionary.com
"one who has a certain function," 1791, from or patterned on French fonctionnaire, a word of the Revolution; from Old French function (see function).
fund (n.) Look up fund at Dictionary.com
1660s, from French fond "a bottom, floor, ground" (12c.), also "a merchant's basic stock or capital," from Latin fundus "bottom, foundation, piece of land," from PIE root *bhudh- "bottom, base" (cognates: Sanskrit budhnah, Greek pythmen "foundation, bottom," Old English botm "lowest part;" see bottom (n.)). Funds "money at one's disposal" is from 1728. Fund-raiser (also fundraiser) first attested 1957.
fund (v.) Look up fund at Dictionary.com
1776, from fund (n.). Related: Funded; funding.
fundament (n.) Look up fundament at Dictionary.com
late 13c., "buttocks, anus," from Old French fondement "foundation, bottom; anus" (12c.), from Latin fundamentum "a foundation," from fundare "to found" (see bottom). So called because it is where one sits.
Alle þe filþ of his magh ['maw'] salle breste out atte his fondament for drede. ["Cursor Mundi," early 14c.]
fundamental (adj.) Look up fundamental at Dictionary.com
mid-15c., "primary, original, pertaining to a foundation," modeled on Late Latin fundamentalis "of the foundation," from Latin fundamentum "foundation" (see fundament). Fundamentals "primary principles or rules" of anything is from 1630s.
fundamentalist (adj.) Look up fundamentalist at Dictionary.com
1920 in the religious sense (as is fundamentalism), from fundamental + -ist. Coined in American English to name a movement among Protestants c.1920-25 based on scriptural inerrancy, etc., and associated with William Jennings Bryan, among others.

Fundamentalist is said (by George McCready Price) to have been first used in print by Curtis Lee Laws (1868-1946), editor of "The Watchman Examiner," a Baptist newspaper. The movement may have roots in the Presbyterian General Assembly of 1910, which drew up a list of five defining qualities of "true believers" which other evangelicals published in a mass-circulation series of books called "The Fundamentals." A World's Christian Fundamentals Association was founded in 1918. The words reached widespread use in the wake of the contentious Northern Baptist Convention of 1922 in Indianapolis.
Fundamentalism is a protest against that rationalistic interpretation of Christianity which seeks to discredit supernaturalism. This rationalism, when full grown, scorns the miracles of the Old Testament, sets aside the virgin birth of our Lord as a thing unbelievable, laughs at the credulity of those who accept many of the New Testament miracles, reduces the resurrection of our Lord to the fact that death did not end his existence, and sweeps away the promises of his second coming as an idle dream. It matters not by what name these modernists are known. The simple fact is that, in robbing Christianity of its supernatural content, they are undermining the very foundations of our holy religion. They boast that they are strengthening the foundations and making Christianity more rational and more acceptable to thoughtful people. Christianity is rooted and grounded in supernaturalism, and when robbed of supernaturalism it ceases to be a religion and becomes an exalted system of ethics. [Laws, "Herald & Presbyter," July 19, 1922]
The original opposition to fundamentalist (within the denominations) was modernist.
A new word has been coined into our vocabulary -- two new words -- 'Fundamentalist' and 'Fundamentalism.' They are not in the dictionaries as yet -- unless in the very latest editions. But they are on everyone's tongue. [Address Delivered at the Opening of the Seminary, Sept. 20, 1922, by Professor Harry Lathrop Reed, "Auburn Seminary Record"]
Applied to other religions, especially Islam, since 1957.
fundamentally (adv.) Look up fundamentally at Dictionary.com
c.1600, from fundamental + -ly (2).
fundus (n.) Look up fundus at Dictionary.com
from Latin fundus "bottom" (see fund (n.)).
funeral (n.) Look up funeral at Dictionary.com
mid-15c., from Middle French funérailles (plural) "funeral rites" (15c.), from Medieval Latin funeralia "funeral rites," originally neuter plural of Late Latin funeralis "having to do with a funeral," from Latin funus (genitive funeris) "funeral, funeral procession, burial rites; death, corpse," origin unknown, perhaps ultimately from PIE root *dheu- (3) "to die." Singular and plural used interchangeably in English until c.1700.
funerary (adj.) Look up funerary at Dictionary.com
1690s, from Late Latin funerarius, from funer-, root of funus (see funeral (n.)).
funereal (adj.) Look up funereal at Dictionary.com
1725, from funeral by influence of Middle French funerail, from Latin funereus "of a funeral," from funus "funeral; death."
funest (adj.) Look up funest at Dictionary.com
"portending death," 1550s (implied in funestal), from Middle French funeste "unlucky" (14c.), from Latin funestus "causing death, destructive; mournful," from funus (see funeral (n.)).
fungal (adj.) Look up fungal at Dictionary.com
1835, from Modern Latin fungalis, from fungus (see fungus).
fungi (n.) Look up fungi at Dictionary.com
Latin plural of fungus.
fungible (adj.) Look up fungible at Dictionary.com
"capable of being used in place of another," 1818, a word in law originally, from Medieval Latin fungibilis, from Latin fungi "perform," as in fungi vice "to take the place" (see function). Earlier as a noun (1765).
fungicide (n.) Look up fungicide at Dictionary.com
1889; see fungus + -cide.
fungo (n.) Look up fungo at Dictionary.com
1867, baseball slang, perhaps from 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).
fungous (adj.) Look up fungous at Dictionary.com
"spongy," early 15c., from Latin fungosus, from fungus (see fungus).
fungus (n.) Look up fungus at Dictionary.com
1520s, from Latin fungus "a mushroom," in English 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).
funicular (adj.) Look up funicular at Dictionary.com
1660s, from Latin funiculus, diminutive of funis "a cord, rope."
funk (n.1) Look up funk at Dictionary.com
"depression, ill-humor," 1743, probably originally Scottish and northern English; earlier as a verb, "panic, fail through panic," (1737), said to be 17c. Oxford University slang, perhaps from Flemish fonck "perturbation, agitation, distress," possibly related to Old French funicle "wild, mad."
funk (n.2) Look up funk at Dictionary.com
"bad smell," 1620s, from dialectal French funkière "smoke," from Old French fungier "give off smoke; fill with smoke," from Latin fumigare "to smoke" (see fume (n.)). In reference to a style of music, it is first attested 1959, a back-formation from funky.
funky (adj.) Look up funky at Dictionary.com
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.) Look up funnel at Dictionary.com
c.1400, from Middle French fonel, from Provençal enfounilh, "a word from the Southern wine trade" [Weekley], 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.) Look up funnel at Dictionary.com
1590s, from funnel (n.). Related: Funneled; funneling.
funnily (adv.) Look up funnily at Dictionary.com
1814, from funny + -ly (2).
funny (adj.) Look up funny at Dictionary.com
"humorous," 1756, from fun + -y (2). Meaning "strange, odd" is 1806, said to be originally U.S. Southern. The two senses of the word led to the retort question "funny ha-ha or funny peculiar," which is attested from 1916. Related: Funnier; funniest. Funny farm "mental hospital" is slang from 1962. Funny bone "elbow end of the humerus" is 1826; funnies "newspaper comic strips" is from 1852.
fur (n.) Look up fur at Dictionary.com
late 14c. "trimming or lining of a garment" (implied c.1300 in surname Furhode "fur hood"), probably from Old French fourrer "to line, sheathe," from fuerre "sheath, covering," from Frankish *fodr or another Germanic source, from Proto-Germanic *fodram "sheath" (cognates: Old Frisian foder "coat lining," Old High German fotar "a lining," German Futter, Gothic fodr "sword sheath").

Sense transferred in English from the notion of a lining to the thing used in it. First applied early 15c. to animal hair still on the animal.
I'le make the fur Flie 'bout the eares of the old Cur. [Butler, "Hudibras," 1663]
As a verb, from c.1300, from Old French fourrer. Related: Furred; furring.
furbelow (n.) Look up furbelow at Dictionary.com
c.1700, alteration 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.) Look up furbish at Dictionary.com
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 (compare Old High German furban "to polish"), from PIE root *prep- "to appear." Related: Furbished; furbishing.
furcate (adj.) Look up furcate at Dictionary.com
"forked," 1819, from Medieval Latin furcatus, from Latin furca (see fork). As a verb, from 1828 (implied in furcated).
furious (adj.) Look up furious at Dictionary.com
late 14c., from Old French furieus (14c., Modern French furieux), from Latin furiosus "full of rage, mad," from furia "rage, passion, 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.) Look up furiously at Dictionary.com
1550s, from furious + -ly (2).
furl (v.) Look up furl at Dictionary.com
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). Related: Furled; furling.
furlong (n.) Look up furlong at Dictionary.com
Old English furlang measure of distance of roughly 220 yards, originally the length of a furrow in the common field of 10 acres, from furh "furrow" + lang "long." The "acre" of the common field being variously measured, the furlong was fixed 9c. on the classical stadium, one-eighth of a Roman mile.
furlough (n.) Look up furlough at Dictionary.com
1620s, vorloffe, from Dutch verlof, literally "permission," from Middle Dutch ver- "completely, for" + laf, lof "permission," which is related to the second element in believe and to leave (n.).

The -gh spelling developed by 1770s and represents an "f" that was once pronounced at the end of the word but disappeared fairly soon thereafter in English.
furlough (v.) Look up furlough at Dictionary.com
1783, from furlough (n.). Related: Furloughed; furloughing.
furnace (n.) Look up furnace at Dictionary.com
early 13c., from Old French fornaise "oven, furnace" (12c.), from Latin fornacem (nominative fornax) "an oven, kiln," related to fornus, furnus "oven," and to formus "warm," from PIE root *gwher- "warm" (cognates: Greek thermos, Old English wearm; see warm (adj.)).
furnish (v.) Look up furnish at Dictionary.com
mid-15c., from Middle French furniss-, present participle stem of furnir "furnish, accomplish," from Old French fornir (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). Meaning "to provide" (something) is from 1520s. Related: Furnished; furnishing.
furnished (adj.) Look up furnished at Dictionary.com
"equipped," 1550s, past participle adjective from furnish. Of rooms, houses, etc. from 1640s.
furnishings (n.) Look up furnishings at Dictionary.com
articles of furniture, c.1600, plural verbal noun from furnish (v.).
furniture (n.) Look up furniture at Dictionary.com
1520s, "act of furnishing," from Middle French fourniture, from fournir "furnish" (see furnish). Sense of "chairs, tables, etc.; household stuff" (1570s) is unique to English; most other European languages derive their words for this from Latin mobile "movable."
furor (n.) Look up furor at Dictionary.com
late 15c., from Middle French fureur, from Latin furor "a ravaging, rage, madness, passion;" related to furia "rage, passion, fury" (see fury).
furore (n.) Look up furore at Dictionary.com
1790, Italian form of furor, borrowed originally in the sense "enthusiastic, popular admiration;" it later descended to mean the same thing as furor and lost its usefulness.