When two drunk people give each other a "fist bump." A drunk gesture after two people agree on something or think something is cool.
After drinking a 12 pack of Michelob Ultra, Tom made a funny joke and gave Mindy a piss fump. When the cast of Jersey Shore get wasted they all want to piss fump.
by dailybragger January 4, 2012
Get the Piss Fumpmug.