theatre of operations vs theater

theatre of operations and theater both are nouns.

Word	Noun	Adjective	Verb	Adverb
theatre of operations	Yes	No	No	No
theater	Yes	No	No	No

As nouns, theatre of operations and theater are synonyms defined as:

theatre of operations and theater: a region in which active military operations are in progress

Other synonyms of theatre of operations include field, field of operations, theater of operations, theatre.

theatre of operations (noun)	theater (noun)
a region in which active military operations are in progress	a building where theatrical performances or motion-picture shows can be presented
	the art of writing and producing plays
	a region in which active military operations are in progress