field of operations vs theater

field of operations and theater both are nouns.

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

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

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

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

field 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