Definitions of 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

  Example: "When the dog entered the stage, he upstaged the actress"

• adjective:   of the back half of a stage

  Example: "She crossed to the upstage chair forcing the lead to turn his back to the audience"

• adjective:   remote in manner

  Example: "He was upstage with strangers"

• adverb:   at or toward the rear of the stage

  Example: "The dancers were directed to move upstage"