[adv] (theater) at or toward the rear of the stage; "the dancers were directed to move upstage"
[adj] of the back half of a stage; "she crossed to the upstage chair forcing the lead to turn his back to the audience"
[v] steal the show, draw attention to oneself away from someone else
[v] move (another actor) upstage, forcing him to turn away from the audience
[v] treat snobbishly, put in one's place