the·a·tre (th???-t?r)n. Variant of theater.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.theatre (????t?) or theatern1. (Theatre) a. a building designed for the performance of plays, operas, etcb. (as modifier): a theatre ticket. c. (in combination): a theatregoer. 2. a large room or hall, usually with a raised platform and tiered seats for an audience, used for lectures, film shows, etc3. (Surgery) Also called: operating theatre a room in a hospital or other medical centre equipped for surgical operations4. (Theatre) plays regarded collectively as a form of art5. (Theatre) the theatre the world of actors, theatrical companies, etc: the glamour of the theatre. 6. a setting for dramatic or important events7. (Theatre) writing that is suitable for dramatic presentation: a good piece of theatre. 8. (Film) US and Austral and NZ the usual word for cinema19. (Military) a major area of military activity: the theatre of operations. 10. (Architecture) a circular or semicircular open-air building with tiers of seats[C14: from Latin the?trum, from Greek theatron place for viewing, from theasthai to look at; related to Greek thauma miracle]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014the?a?ter or thea?tre (??i ? t?r, ??i?-) n. 1. a building, part of a building, or an outdoor area for dramatic presentations, stage entertainments, or motion-picture shows. 2. a room or hall with tiers of seats, used for lectures, surgical demonstrations, etc.: Students crowded into the operating theater. 3. a. the theater, dramatic performances as a branch of art; the drama, esp. as a profession. b. a particular type, style, or category of this art: musical theater. 4. dramatic works collectively, as of literature, a nation, or an author (often prec. by the): the Elizabethan theater. 5. the quality or effectiveness of dramatic performance. 6. a. a place of action; area of activity. b. an area or region where military operations are under way: the Pacific theater. 7. a natural formation of land rising by steps or gradations. [1325?75; Middle English