fuck

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To have sexual intercourse with.
2. v. To take advantage of, betray, or cheat; victimize.
3. v. Used in the imperative as a signal of angry dismissal.
4. v. To engage in sexual intercourse.
5. v. To act wastefully or foolishly.
6. v. To interfere; meddle. Often used with with.
7. n. An act of sexual intercourse.
8. n. A partner in sexual intercourse.
9. n. A despised person.
10. n. Used as an intensive: What the fuck did you do that for?
11. interj. Used to express extreme displeasure.
12. fuck off Used in the imperative as a signal of angry dismissal.
13. fuck off To spend time idly.
14. fuck off To masturbate.
15. fuck over To treat unfairly; take advantage of.
16. fuck up To make a mistake; bungle something.
17. fuck up To act carelessly, foolishly, or incorrectly.
18. fuck up To cause to be intoxicated.

Wiktionary

1. interj. Expressing dismay or discontent.
2. v. (often) To have sexual intercourse, to copulate.
3. v. (often) To insert one’s penis, or a dildo or other phallic object, into a specified orifice or cleft.
4. v. To put in an extremely difficult or impossible situation.
5. v. (usually) To break; to destroy.
6. v. To defraud.
7. v. To play with; to tinker.
8. v. used to emphasize displeasure with someone or something
9. v. To lose care for, to forget, to no longer regard as important.
10. n. An act of sexual intercourse.
11. n. A sexual partner.
12. n. A highly contemptible person.
13. n. Male ejaculate.
14. n. A thing of no value, a small amount.
15. n. A large amount.
16. adv. Used as an intensifier for the words "yes" and "no".

GNU Webster's 1913

1. v. to have sexual intercourse (with).
2. n. A slang term for sexual intercourse.

WordNet 3.0

1. n. slang for sexual intercourse
2. v. have sexual intercourse with