(n.) A room before, or forming an entrance to, another\; a waiting room.

L R acting area antechamber anteroom apron apron stage audience chamber backstage band shell bandstand board bridge coulisse dock dressing room flies fly floor fly gallery forestage grid gridiron lightboard lounge orchestra orchestra pit performing area pit presence chamber proscenium proscenium stage reception room shell side room stage stage left stage right switchboard the boards throne room waiting room wardroom wings