Grandaddydon Share definition Flag A word used to express the extreme apogee of utlra cool - be it a person, event or thing. "Dude, that right there is the Grandaddydon of exhaust pipes!" Grandaddydon by Kev76 December 24, 2008 0 0 Get merch Get the Grandaddydon mug. Buy Now — $32.95 See more merch
