n. sl. 1 a esp. US an athlete or horse entered in a competition by fraudulent means, esp. as a substitute. b a person's double, esp. an imposter. 2 Austral. a the fastest shearer in a shed. b a stockman or station hand. 3 a person who rings, esp. a bell-ringer. be a ringer (or dead ringer) for resemble (a person) exactly.
[ RING(2) + -ER(1) ]