One whose oral cavity is used exclusively for the purpose of giving head.
"Piss off out of my face you nasty little mouthwhore".
a guy or girl who makes out with anyone and everyone, usually the people they kiss are close together chronilogically.
1: "I heard Barbara made out with Johnny and Mike at the party on Friday."
2: "Ew. Gross. I heard she was kissing Shane, too."
1: "Gah, she's such a mouthwhore."