When engaing in a debate and a person says something so outlandishly stupid, incoherent, or contradictory, that their opponent is left utterly speechless and dumbfounded. Usually used as a last last resort by somebody who's losing a debate and who knows his premise is invalid.

when you're hungover as shit after a spending a night drunk as a skunk

When the ass cheeks bang the thighs and he hits the final blow