To hit, strike, or beat something vigorously with a stick. Usually while very upset or disappointed. But, it must be with a stick, or else it's not anundering.
Amber went to chemistry class and realized there was a test she forgot to study for. She was so angry, she wanted to anunder somebody.
After my best friend told me I was ugly, I wanted to do some serious anundering.
Ruler of Lake Titicaca. Rumored to have a bunghole that gets very angry if it does not receive toilet paper. Cornholio the Great is often seen walking around with his shirt over his head and his hands in the air, chanting songs about his power, and his bunghole.
"I am Cornholio! You do not want to face the wrath of my bunghole, for I need TP!"
Butthead: Shut up, Beavis! (uh huh huh huh)
Beavis: Um, okay. (heh heh heh heh).