(Diaper lover slang) To bounce oneself up-and-down on an adult rocking horse with springs while wearing a diaper with a firm ball of warm poop in the taint region.
Hunker Down game is a game played at hurricane parties. You watch the weather report and everytime the weatherman or news guy says "hunker down" you take a shot. By the time the electricity is out, you don't even care any more.