<p><strong>Noun</strong></p><ul><li>a building, part of a building, or outdoor area for housing dramatic performances or stage entertainments, or for showing movies</li><li>the audience at a theatrical performance or movie: The whole theater was weeping</li><li>a theatrical or acting company</li><li>a room or hall, fitted with tiers of seats rising like steps, used for lectures, surgical demonstrations, etc.: Students crowded into the operating theater</li><li>the theater, dramatic performances as a branch of art; the field or discipline of staged drama: an actress devoted to the theater</li><li>dramatic works collectively, as of literature, a nation, or an author: the theater of Ibsen</li><li>the quality or effectiveness of dramatic performance: bad theater; good theater; bad theater; pure theater</li><li>a place of dramatic action, especially during a war: theater of war; the Pacific theater during World War II</li><li>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): Public health experts have said that the time and money spent on cleaning may be unnecessary hygiene theater</li><li>a natural formation of land rising by steps or gradations</li></ul>