a building, part of a building, or outdoor area for housing dramatic presentations, stage entertainments, or motion-picture shows.

the audience at a theatrical or motion-picture performance

The theater wept.

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.

the theater, dramatic performances as a branch of art; the drama

an actress devoted to the theater.

dramatic works collectively, as of literature, a nation, or an author (often prec. by the )

the theater of Ibsen.

the quality or effectiveness of dramatic performance

good theater; bad theater; pure theater.

a place of action; field of operations.

a natural formation of land rising by steps or gradations.

noun

amphitheater , arena , assembly hall , auditorium , barn , boards , cinema , coliseum , concert hall , deck , drama , drive-in , footlights , hall , hippodrome , house , locale , movie , movie house , oak , odeum , opera house , playhouse , room , scene , show hall , site , theatre , battleground , broadway , field , lyceum , odeon , stage