ringer

noun

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