When you have a headache before a night of epic drinking. It's been compared to prophecy as it predicts that the alcohol consumption will be so legendary it already has ramifications.
"Dude I think I have a hangunder." Dude 1
"Man I am so hungunder I can't even remember what I'm going to do tonight." Dude 2
Term originating in South Louisiana that involves slapping a girl in the face with your penis. While extremely similar to mushroom stamping, the "hangartner" requires one to cum in the girl's hair immediately after slapping her in the face
Dude! Did you see that chick with the crunchyhair and red marks on her face? She must have just been hangartnered!