3. any place where events take place; scene of operations; specif., an area of military operations, as in a war
⇒ a commander in the Southern Pacific theater
Webster’s New World College Dictionary, Fourth Edition, compiled by the
editors of Webster’s New World Dictionaries. Copyright © 2010 by Houghton
Mifflin Harcourt. Published by Houghton Mifflin Harcourt. All rights reserved.
Word origin of 'theater'ME theatre < OFr < L theatrum < Gr theatron < base of theasthai, to see, view < IE base *dhāu-, to see > Gr thauma, miracle