- The twenty-fourth letter of the Appendix:Roman script, English alphabet, preceded by W and followed by Y, and representing /ks/, /gz/, or (at the beginning of words) /z/.
- Any mark that looks like that letter, such as such a mark made by a person who cannot read or write.
- (lacrosse) The spot behind the goal.
- (rfd-sense) Surname taken by w:Malcolm X, Malcolm Little who would henceforth call himself Malcolm X.
- (context, Former, _, British, _, film certificate) Suitable only for those aged 16 or (later) 18 years and over.
- (context, movie rating) Obscene.