1 definition by fasfdaf

Somone who is always on a certain persons side. Always agrees with specified person. Laughs at stupid jokes person says just so they won't get made fun of by person.
Leroy (to Artez): Man you look like a sexy moose

James(cosigner):HaHaHa man you to funny Leroy, you need your own show

Artez (to James):Man James you a co-signer man always laughing at Leroy lame jokes
by fasfdaf October 20, 2005
Get the co-signer mug.