f-word

Short definition from Wiktionary

Noun

1. 1
   The word fuck (or inflected forms like fucking) or fucker.
2. 2
   The word fag or faggot.
3. 3
   Any word beginning with f that is not normally taboo but is considered (often humorously) to be so in the given context.
4. 4
   Alternative form of f-word.
5. 5
   Alternative letter-case form of f-word.
6. 6
   Alternative letter-case form of f-word.

Verb

1. 1
   To use vulgarities, especially the word fuck.