stand-in /ˈstænˌdɪn/
  代替演員,替身,有利地位
  stand-in
       n : someone who takes the place of another (as when things get
           dangerous or difficult); "the star had a stand-in for
           dangerous scenes"; "we need extra employees for summer
           fill-ins" [syn: substitute, relief, reliever, backup,
            backup man, fill-in]