Honorific alternative letter-case form of who, sometimes used when referring to God or another important figure who is understood from context.

(fandom slang) The television show Doctor Who.

(colloquial, rhetorical question, sarcastic, humorous) Used as a retort or comeback, often to deprecate oneself or another for excessive concern or attention to detail.

Used by a phone-call receiver to ask the identity of the caller.

(defensively) Used to ask a stranger asking a question to identify themselves

A situation in which confusion arises due to homophones and similar misunderstandings.

plural of who's on first

According to whose authority (especially in defiance) / Nobody knows; it is difficult to judge

A humorous and/or sarcastic statement of (often sexual) superiority over someone else. / (BDSM) An assertion that one is the dominant in a relationship or situation.

A conventional phrase used when talking to parrots.