A dude's filthy, dirty cock after having sex with a prostitute, a crack whore, meth whore, or just an all around cock hopping ho.
After a quick $10 bang with the local prostitite on the way home from work, Roger stopped at the gas station to wash the stink off his Grunge Knob before going home to get a little head from his wife.
by Eaton Holgoode April 17, 2015
Get the Grunge Knobmug.