To hold onto someones beer while they are doing something that uses both of their hands (using the bathroom, digging for money, etc). Can also be used to hold other things, but it's main purpose is beer holding.
Hey man, pronking? I gotta piss.
Dude, pronking, I can't find my fucking money.
From the word pronk, used to indicate good or very.
Pronking is a term everyone in Virginia's 11th district uses!