Quick definitions from WordNet (upstage)
▸ verb: move (another actor) upstage, forcing him to turn away from the audience
▸ verb: treat snobbishly, put in one's place
▸ verb: steal the show, draw attention to oneself away from someone else ("When the dog entered the stage, he upstaged the actress")
▸ adjective: of the back half of a stage ("She crossed to the upstage chair forcing the lead to turn his back to the audience")
▸ adjective: remote in manner ("He was upstage with strangers")
▸ adverb: at or toward the rear of the stage ("The dancers were directed to move upstage")
▸ Also see upstage
▸ verb: move (another actor) upstage, forcing him to turn away from the audience
▸ verb: treat snobbishly, put in one's place
▸ verb: steal the show, draw attention to oneself away from someone else ("When the dog entered the stage, he upstaged the actress")
▸ adjective: of the back half of a stage ("She crossed to the upstage chair forcing the lead to turn his back to the audience")
▸ adjective: remote in manner ("He was upstage with strangers")
▸ adverb: at or toward the rear of the stage ("The dancers were directed to move upstage")
▸ Also see upstage