fistload. Share definition Flag anything held in the hand to be used as a weapon, brass knuckles, rolls of pennies or even a small AA flashlight. the dude hit him with a fistload. he laid that punks ass out! fistload. by bunker stevens September 25, 2012 0 0 Get merch Get the fistload. mug. Buy Now — $32.95 See more merch