theatre vs field of operations

theatre and field of operations both are nouns.

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

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

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

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

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