theater vs downstage

theater and downstage both are nouns.

Word	Noun	Adjective	Verb	Adverb
theater	Yes	No	No	No
downstage	Yes	Yes	No	Yes

theater (noun)	downstage (noun)
a building where theatrical performances or motion-picture shows can be presented	the front half of the stage (as seen from the audience)
the art of writing and producing plays
a region in which active military operations are in progress

theater (adjective)	downstage (adjective)
	of the front half of a stage

theater (adverb)	downstage (adverb)
	at or toward the front of the stage