A place or building, consisting of a stage and seating, in which an audience gathers to watch plays, musical performances, public ceremonies, and so on.

A region where a particular action takes place; a specific field of action, usually with reference to war.

A lecture theatre.

(medicine) An operating theatre or locale for human experimentation.

(US) A cinema.

Drama or performance as a profession or art form.

Any place rising by steps like the seats of a theater.

(figurative, derogatory, often following a noun used attributively) A conspicuous but unproductive display of action.