v. Dipping, driving, or penetrating into a vagina, mouth, or butt hole using one's testicles.
similar words: Teabag, Balldip
"I just dunktanked that girl in the ass so hard!"
"My balls are so big that I was only able to dunktank one of them!"
She really wanted him to dunktank her mouth.
He got off on dunktanking chicks.