- a building, part of a building, or outdoor area for housing dramatic performances or stage entertainments, or for showing movies.
- the audience at a theatrical performance or movie: The whole theater was weeping.
- a theatrical or acting company.
- a room or hall, fitted with tiers of seats rising like steps, used for lectures, surgical demonstrations, etc.: Students crowded into the operating theater.
- dramatic performances as a branch of art; the field or discipline of staged drama: an actress devoted to the theater.
- dramatic works collectively, as of literature, a nation, or an author: the theater of Ibsen.
- the quality or effectiveness of dramatic performance: good theater;bad theater;pure theater.
- a place of dramatic action, especially during a war: the Pacific theater during World War II.
- a public display of action or speech that gives a false impression of accomplishing or promising something, merely for the sake of appearances (often used in combination): Washington D.C.'s Metro transit system has instituted random bag searches, and many travelers are just as unhappy about the security theater on the train as in the airport.Public health experts have said that the time and money spent on cleaning may be unnecessary hygiene theater.Companies need to go beyond diversity theater and commit to long-term, concrete metrics for change.Forget all his blustering about doing what's best for our city—it's just theater to please his union masters and protect his political base.
- a natural formation of land rising by steps or gradations.
