A woman that is such a fucking whore and such a tramp that the only way to describe her is to pair her immense trampness with godzilla, hence tramzilla. This term only applies to those women who have slept with 30 men or more. Or a girl that all your friends did in the butt one night. Either way.
Mike: Dude...i hooked up with Tammy last night, isnt she so hot.
Aaron: No way dude, that bitch is the biggest trampzilla in the greater metro area.