When you absolutely plough the shit out of the side of someone's thigh with your knee, hence named because they will be walking like a grandad for the rest of the day.
by Frankoyo December 02, 2013
by Steelbeast November 01, 2020
by grandads girl LOL January 23, 2009
by Jimby Bobbinson May 03, 2018
Your grandad that’s why
by Crjames September 27, 2019
Hi grandad
by Rugbyface10 December 17, 2018
by Chicken83 April 08, 2007