Well, I don't know why, but there seems to be so much confusion about this word. Not to offend anyone, here's what websters dictionary had to say:
VERB: Inflected forms: ****ed, ****?ing, ****s
TRANSITIVE VERB: 1. Vulgar Slang To have sexual intercourse with.
2. To take advantage of, betray, or cheat; victimize.
3. Used in the imperative as a signal of angry dismissal.
INTRANSITIVE VERB: 1. To engage in sexual intercourse.
2. To act wastefully or foolishly.
3. To interfere; meddle. Often used with with.
NOUN: 1. An act of sexual intercourse.
2. A partner in sexual intercourse.
3. A despised person.
4. Used as an intensive: What the **** did you do that for?
INTERJECTION: Used to express extreme displeasure.
PHRASAL VERBS: **** off 1. Used in the imperative as a signal of angry dismissal.
2. To spend time idly.
3. To masturbate. **** over To treat unfairly; take advantage of. **** up 1. To make a mistake; bungle something.
2. To act carelessly, foolishly, or incorrectly.
3. To cause to be intoxicated.
ETYMOLOGY: Middle English, attested in pseudo-Latin fuccant, (they) ****, deciphered from gxddbov.
WORD HISTORY: The obscenity **** is a very old word and has been considered shocking from the first, though it is seen in print much more often now than in the past. Its first known occurrence, in code because of its unacceptability, is in a poem composed in a mixture of Latin and English sometime before 1500. The poem, which satirizes the Carmelite friars of Cambridge, England, takes its title, ?Flen flyys,? from the first words of its opening line, ?Flen, flyys, and freris,? that is, ?fleas, flies, and friars.? The line that contains **** reads ?Non sunt in coeli, quia gxddbov xxkxzt pg ifmk.? The Latin words ?Non sunt in coeli, quia,? mean ?they [the friars] are not in heaven, since.? The code ?gxddbov xxkxzt pg ifmk? is easily broken by simply substituting the preceding letter in the alphabet, keeping in mind differences in the alphabet and in spelling between then and now: i was then used for both i and j; v was used for both u and v; and vv was used for w. This yields ?fvccant [a fake Latin form] vvivys of heli.? The whole thus reads in translation: ?They are not in heaven because they **** wives of Ely [a town near Cambridge].?