What is the meaning of Theater?

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.

An operating theatre or locale for human experimentation.

A cinema.

Drama or performance as a profession or art form.

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

A conspicuous but unproductive display of action.

theater (US), theatre (Commonwealth): either drama, the art form, or a drama theater (building)

A theatre open to the sky; an amphitheatre.

Any stage which plays and performances take place at.

A whorehouse.

Source: wiktionary.org