"to pour out, spill," late 14c., from French effuser or directly from Latin effusus "poured out," past participle of effundere "pour forth, spread abroad; to lavish, squander, waste," from assimilated form of ex "out" (see ex-) + fundere "to pour" (from nasalized form of PIE root *gheu- "to pour"). Related: Effused; effusing. Not to be confused with eff youse.
British slang word with varied senses, not all of them certainly connected; see Partridge, who lists two noun uses: "female pudenda" (c. 1845), which might be back-slang from fan, shortening of fanny (in the British sense); and "nothing," in prostitutes' slang from c. 1940; a verbal use, a euphemism for fuck (v.) in oaths, imprecations, expletives (as in naff off), 1959, "making it slightly less obvious than eff" [Partridge]; and an adjective naff "vulgar, common, despicable," which is said to have been used in 1960s British gay slang for "unlovely" and thence adopted into the jargons of the theater and the armed forces.
"to have sexual intercourse with" (transitive), until recently a difficult word to trace in usage, in part because it was omitted as taboo by the editors of the original OED when the "F" entries were compiled (1893-97). Johnson also had excluded the word, and fuck wasn't in a single English language dictionary from 1795 to 1965. "The Penguin Dictionary" broke the taboo in the latter year. Houghton Mifflin followed, in 1969, with "The American Heritage Dictionary," but it also published a "Clean Green" edition without the word, to assure itself access to the public high school market.
Written form attested from at least early 16c.; OED 2nd edition cites 1503, in the form fukkit, and the earliest attested appearance of current spelling is 1535 ("Bischops ... may fuck thair fill and be vnmaryit" [Sir David Lyndesay, "Ane Satyre of the Thrie Estaits"]). Presumably it is a more ancient word, but one not written in the kind of texts that have survived from Old English and Middle English [September 2015: the verb appears to have been found recently in an English court manuscript from 1310]. Buck cites proper name John le Fucker from 1278, but that surname could have other explanations. The word apparently is hinted at in a scurrilous 15c. poem, titled "Flen flyys" ["Fleas, Flies (and Friars)"], written in bastard Latin and Middle English. The relevant line reads:
Non sunt in celi
quia fuccant uuiuys of heli
"They [the monks] are not in heaven because they fuck the wives of [the town of] Ely." Fuccant is pseudo-Latin, and in the original it is written in cipher. The earliest examples of the word otherwise are from Scottish, which suggests a Scandinavian origin, perhaps from a word akin to Norwegian dialectal fukka "copulate," or Swedish dialectal focka "copulate, strike, push," and fock "penis."
Another theory traces the Modern English verb to Middle English fyke, fike "move restlessly, fidget" (see fike) which also meant "dally, flirt," and probably is from a general North Sea Germanic word (compare Middle Dutch fokken, German ficken "fuck," earlier "make quick movements to and fro, flick," still earlier "itch, scratch;" the vulgar sense attested from 16c.). This would parallel in sense the vulgar Middle English term for "have sexual intercourse," swive, from Old English swifan "to move lightly over, sweep" (see swivel). But OED remarks that these "cannot be shown to be related" to the English word. Liberman has this to say:
Germanic words of similar form (f + vowel + consonant) and meaning 'copulate' are numerous. One of them is G. ficken. They often have additional senses, especially 'cheat,' but their basic meaning is 'move back and forth.' ... Most probably, fuck is a borrowing from Low German and has no cognates outside Germanic.
Chronology and phonology rule out Shipley's attempt to derive it from Middle English firk "to press hard, beat." The unkillable urban legend that this word is an acronym of some sort (a fiction traceable on the internet to 1995 but probably predating that), and the "pluck yew" fable, are results of ingenious trifling (also see here). The Old English verb for "have sexual intercourse with" was hæman, from ham "dwelling, home," with a sense of "take home, co-habit." French foutre and Italian fottere seem to resemble the English word but are unrelated, descending rather from Latin futuere, which perhaps is from PIE root *bhau- "to strike," extended via a figurative use "from the sexual application of violent action" [Shipley; compare the sexual slang use of bang, etc.].
Fuck was outlawed in print in England (by the Obscene Publications Act, 1857) and the U.S. (by the Comstock Act, 1873). The word continued in common speech, however. During World War I:
It became so common that an effective way for the soldier to express this emotion was to omit this word. Thus if a sergeant said, 'Get your ----ing rifles!' it was understood as a matter of routine. But if he said 'Get your rifles!' there was an immediate implication of urgency and danger. [John Brophy, "Songs and Slang of the British Soldier: 1914-1918," pub. 1930]
The legal barriers against use in print broke down in mid-20c. with the "Ulysses" decision (U.S., 1933) and "Lady Chatterley's Lover" (U.S., 1959; U.K., 1960). The major breakthrough in publication was James Jones' "From Here to Eternity" (1950), with 50 fucks (down from 258 in the original manuscript).
The abbreviation F (or eff) probably began as euphemistic, but by 1943 it was regarded as a cuss word in its own right. In 1948, the publishers of "The Naked and the Dead" persuaded Norman Mailer to use the euphemism fug. When Mailer later was introduced to Dorothy Parker, she greeted him with, "So you're the man who can't spell 'fuck' " [The quip sometimes is attributed to Tallulah Bankhead]. As a written euphemism, muck is attested by 1929 (Hemingway used it in "For Whom the Bell Tolls," 1940). Related: Fucked; fucking.
Fuck-all "nothing" first recorded 1960. Verbal phrase fuck up "to ruin, spoil, destroy" is attested from c. 1916. A widespread group of Slavic words (such as Polish pierdolić) can mean both "fornicate" and "make a mistake." Fuck off is attested from 1929; as a command to depart, by 1944. Egyptian legal agreements from the 23rd Dynasty (749-21 B.C.E.) frequently include the phrase, "If you do not obey this decree, may a donkey copulate with you!" [Reinhold Aman, "Maledicta," Summer 1977].