Extremely powerful insult usually directed towards someone when a more creative term than 'asshole' is needed. The implication is that the person is so amoral/stupid that they would fuck a gunt as opposed to a cunt. Reasons for this lack of proper copulation technique could range from indifference to desperation to a perverted sense of the need to humiliate oneself and sexual partner simultaneously.
Person A: Did you hear about Ronnie? He date-raped that retarded girl on Pearson Avenue.
Person B: Mikey's sister?!? That guntfucker! I'm gonna kill him.
When a man possesses such a freakishly large penis that he ruptures his partner's abdominal cavity during intercourse, resulting in penetration of the intestines.
"Being hung like a horseain't all it's cracked up to be. I accidentally gave my girlfriend a gutsfuck the other night, and now she's in the hospital."
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.