Etymology: (1325–75; ME < L theātrum < Gk théātron seeing place, theater =theā-, s. of theâsthai to view +-tron suffix of means or place)
Definition of 'theater'
Princeton's WordNet
1. (noun)theater, theatre, house a building where theatrical performances or motion-picture shows can be presented "the house was full"
2. (noun)dramaturgy, dramatic art, dramatics, theater, theatre the art of writing and producing plays
3. (noun)field, field of operations, theater, theater of operations, theatre, theatre of operations a region in which activemilitaryoperations are in progress "the army was in the field awaiting action"; "he served in the Vietnam theater for three years"