A homosexual woman. (slander)
Man: "How did I know my girlfriend would run off with a clam bumper?"
door Spud 27 januari 2004
"Gee, I never would've guessed that Rosie O'Donnell was a clam bumper.", he said sarcastically.
door Mike Stander 1 augustus 2003
One definition of lesbians, (clam meaning vagina) insisting that the two women have sex by rubbing one of their vaginas against the others vagina.
Cindy and Martha love eachother, they are probably clam bumpers.
door leanna :) 7 april 2006