Top definition
A woman who is obsessed with having sex with men. She is crazy about a man's dick and grabs the crotch's of strange men on the street. A petermonster is pretty hot but men who know her stay away because they are scared of getting diseases.
"That girl is pretty hot! What's her name?" he exclaimed to his friend after a woman humped his leg on the dance floor. "Don't mess with her man, she's a petermonster."
by Ginabob420 May 14, 2015
Happy St. Patties Day!