ringer

/ˈrɪŋər/
noun
  1. A person or thing that rings, especially someone who rings bells.
    • The ringer signaled the start of the ceremony with a clear chime.
    • The church ringer pulled the rope to start the Sunday bells.
    • She trained as a ringer for the local bell tower.
  2. A person or thing that closely resembles another; a look-alike or impostor.
    • The police arrested a ringer who had stolen the celebrity's identity.
    • Her new puppy is a ringer for the one she had as a child.
    • That actor is a dead ringer for my old math teacher.
  3. In sports or games, a player who is secretly substituted for a weaker player to gain an unfair advantage.
    • The team was disqualified for using a ringer in the championship match.
    • The coach denied hiring a ringer for the softball tournament.
    • They brought in a ringer to win the trivia contest.