Origins of "fuck":
[Probably cognate with Dutch fokken to mock (15th cent.), to strike (1591), to fool, gull (1623), to beget children (1637), to have sexual intercourse with (1657), to grow, cultivate (1772), Norwegian regional fukka to copulate, Swedish regional fokka to copulate (compare Swedish regional fock penis), further etymology uncertain: perhaps < an Indo-European root meaning ?to strike? also shown by classical Latin pugnus fist (see PUGNACIOUS adj.). Perhaps compare Old Icelandic fjúka to be driven on, tossed by the wind, feykja to blow, drive away, Middle High German fochen to hiss, to blow. Perhaps compare also Middle High German ficken to rub, early modern German ficken to rub, itch, scratch, German ficken to have sexual intercourse with (1558), German regional ficken to rub, to make short fast movements, to hit with rods, although the exact nature of any relationship is unclear.
On the suggested Indo-European etymology (and for a suggestion that the word was probably a strong verb during its earlier history in English) see especially R. Lass ?Four letters in search of an etymology? in Diachronica 12 (1995) 99-111.
It seems certain that the word was current (in transitive use) before the early 16th cent., although the only surviving attestation shows a Latin inflectional ending in a Latin-English macaronic text: see quot. a1500 and note at sense 1b. See discussion at FUCKER n. on various supposed (but very doubtful) earlier occurrences of the word in surnames. However, if the bird name WINDFUCKER n. (also FUCKWIND n.) is ultimately related, it is interesting to note an occurrence of the surname Ric' Wyndfuk', Ric' Wyndfuck' de Wodehous' (1287 in documents related to Sherwood Forest) which may show another form of the bird name. Use in a sense ?to strike? could perhaps also be reflected by the surname Fuckebegger' (1287); perhaps compare the Anglo-Norman surname Butevilein (literally ?strike the churl or wretch?), found in the 12th and 13th centuries. For discussion of a possible (although not certain) occurrence of FUCKING n. in a field name fockynggroue recorded in a Bristol charter of c1373 see R. Coates ?Fockynggroue in Bristol? in N. & Q. 252 (2007) 373-6.
Many alternative theories have been suggested as to the origin of this word. Explanations as an acronym are often suggested, but are obviously much later rationalizations.
Despite widespread use over a long period and in many sections of society, fuck remains (and has been for centuries) one of the English words most avoided as taboo. Until relatively recently it rarely appeared in print, and there are still a number of euphemistic ways of referring to it (compare e.g. EFF v., FECK v.2, F-WORD n., F-WORD v.). It is also frequently written with asterisks, dashes, etc., to represent suppressed letters, so as to avoid the charge of obscenity. Modern quotations for the term before the 1960s typically come from private sources or from texts which were privately printed, especially on the mainland of Europe. Bailey (1721) included the word (defined ?Foeminam Subagitare?), but not Johnson (1755), Webster (1828), and later 19th- and early 20th-cent. dictionaries. Partridge (1937) included the word as ?f*ck?, noting that ?the efforts of James Joyce and D. H. Lawrence have not restored it to its orig. dignified status [in dictionaries]?. A gradual relaxation in the interpretation of obscenity laws in the U.K. followed the unsuccessful prosecution in 1960 of Penguin Books Ltd. (under the Obscene Publications Act of 1959) for the publication in the London edition of D. H. Lawrence's Lady Chatterley's Lover (see, for example, quot. 1928 at sense 1b). The first modern dictionary of general English to include an entry for the verb fuck was G. N. Garmonsway's Penguin English Dictionary of 1965.]