Noun > Ringer

(count)

1 : someone who rings a bell

a bell ringer

2 : the part of a telephone that rings to signal that someone is calling

Turn off the ringer on the telephone.

3 : informal : a person or animal that enters a contest illegally by using a false name, pretending not to have much skill, etc.

One of the players on the winning team was a ringer.

4 : informal : someone who looks very much like another person

He’s a ringer for the President.

She’s a dead ringer for my cousin Julie. (=she looks exactly like my cousin Julie)