Answer: supernumerary

AnswerCrossword Clue
SUPERNUMERARYActor in a mob scene
supernumerary(of an actor) Appearing on stage but not speaking
supernumeraryabove the stated, usual or necessary number / an actor without a speaking part
supernumeraryNot wanted or needed; redundant
supernumerary(of a person) Not belonging to a regular staff but engaged for extra work
supernumeraryDenoting a structure or organ occurring in addition to the normal ones
supernumeraryPresent in excess of the normal or requisite number, in particular