Meaning

• 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.

  "His grandfather was in the Pacific theater during the war."

• A lecture theatre.

• An operating theatre or locale for human experimentation.

  "This man is about to die, get him into theater at once!"

• A cinema.

  "We sat in the back row of the theater and threw popcorn at the screen."

• Drama or performance as a profession or art form.

  "I worked in theater for twenty-five years."

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