region vs theatre

region and theatre both are nouns.

Word	Noun	Adjective	Verb	Adverb
region	Yes	No	No	No
theatre	Yes	No	No	No

As nouns, theatre is a hyponym of region; that is, theatre is a word with a more specific, narrower meaning than region:

region (noun)	theatre (noun)
a part of an animal that has a special function or is supplied by a given artery or nerve	a building where theatrical performances or motion-picture shows can be presented
a knowledge domain that you are interested in or are communicating about	the art of writing and producing plays
the extended spatial location of something	a region in which active military operations are in progress
a large indefinite location on the surface of the Earth
the approximate amount of something (usually used prepositionally as in `in the region of')