ringer in WordNet English dictionary

1. a person who rings church bells (as for summoning the congregation)
   toller  bell ringer  ringer 
   
2. a person who is almost identical to another
   ringer  dead ringer  clone 
   
3. (horseshoes) the successful throw of a horseshoe or quoit so as to encircle a stake or peg
   ringer 
   
4. a contestant entered in a competition under false pretenses
   ringer