left stage vs stage left

left stage and stage left both are nouns.

Word	Noun	Adjective	Verb	Adverb
left stage	Yes	No	No	No
stage left	Yes	No	No	No

As nouns, left stage and stage left are synonyms defined as:

left stage and stage left: the part of the stage on the actor's left as the actor faces the audience

left stage (noun)	stage left (noun)
the part of the stage on the actor's left as the actor faces the audience	the part of the stage on the actor's left as the actor faces the audience