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 2, 2013
Get the Grandadmug. by Steelbeast November 1, 2020
Get the Grandadmug. by grandads girl LOL January 23, 2009
Get the Grandadmug. by Jimby Bobbinson May 3, 2018
Get the Grandadmug. Your grandad that’s why
by Crjames September 27, 2019
Get the Grandadmug. Hi grandad
by Rugbyface10 December 17, 2018
Get the Grandadmug. by Chicken83 April 8, 2007
Get the grandadmug.