backstage

Short definition from Wiktionary

Adjective

1. 1
   Relating to, or situated in the area behind a stage.
2. 2
   Secret, concealed from the public.

Adverb

1. 1
   Towards the area behind the stage.
2. 2
   Out of view of the public.

Noun

1. 1
   The area behind a stage out of view of the audience where performers wait to give their show; especially that of the dressing rooms.
2. 2
   The private portion of the space used by a business or enterprise.