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."
Any individual who is known for having a wang in the mouth - perhaps even multiple wangs at one time. A mouth whore is so obsessed with having wangs in or around his or her mouth that on the odd occasion that there is no wang in the immediate vicinity, this person will waste away just thinking of how many wangs might fit in his or her mouth on a good day.
May I have an order of regular degular buttermilk pancakes? Without all the added jazz? Hold the blueberry smiley face, strawberry glaze, chocolate chips and whipped cream.