ringer
n.a person who is secretly very good at a sport or game but joins a team of beginners to help them win. It can also mean someone who looks exactly like another person.
n.a person or thing that is highly similar to another; also, a highly skilled competitor who enters a contest under false pretences to gain an advantage. Often used in the phrase 'dead ringer' to describe a perfect physical resemblance.
“He is a dead ringer for that famous actor.”
“The other team brought in a ringer from the semi-pro league just to win the local charity tournament.”
“Suspicions arose when the supposedly amateur cyclist outperformed the veterans, leading the committee to investigate whether the team had recruited a ringer to secure the sponsorship prize.”
Commonly appears in the idiomatic expression 'dead ringer' followed by the preposition 'for'.
From Middle English ringere, rynger, ryngar, equivalent to ring (“to sound a bell”) + -er.
From ring (“to surround”) + -er.
Unknown. Probably so named after the custom of ringing a bell to denote the winner of a contest or competition.
Some senses may derive from ring the changes (“run through variations; enliven; pass counterfeit money; trick a shopkeeper into giving too much change”).
Unclear. Compare ring of truth.
From ring + -er, from the noun.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.