backstage (Adjective) — Concealed from public view or attention. ex. "backstage political meetings"
backstage (Noun) — A stage area out of sight of the audience.
backstage (Adverb) — Out of view of the public; behind the scenes. ex. "Working backstage to gain political support for his proposal" ex. "many private deals were made backstage at the convention"
backstage (Adverb) — In or to a backstage area of a theatre. ex. "costumes were changed backstage"