backstage
n. place B1 Intermediate US //ˈbækˈsteɪdʒ// UK //bˈæksteɪdʒ// back·stage
n. in the area behind the stage where the audience cannot see you. You use this to talk about where actors or musicians prepare for a show.
n. situated or occurring behind the stage in a theatre or concert hall, particularly in the dressing rooms or wings. Often describes activities hidden from public view.
The actors are getting ready backstage.
After the concert ended, a few lucky fans were invited backstage to meet the lead singer.
While the audience marveled at the seamless scene changes, a dozens of technicians worked frantically backstage to coordinate the complex machinery and lighting cues.
From back + stage.
Usage
Typically functions as an adverb of place following a verb of motion or position; can also be used as an adjective before a noun.