This definition refers to a guy's inability to aim his cock when he's taking a piss. This lack of skill is quite apparent when the perp is done and there are yellow pee stains on the toilet rim and floor. Some douche bags don't even bother to lift the toilet seat and piss all over it as well. Ya gotta wonder when you see pools of pee on the floor in front of a urinal only a few inches from a dude's dick how he can manage to fuck that process up. Perhaps some day somebody will patent crosshairs for dicks so a sporting guy can practice his marksmanship.
Guys; don't be a piss poor shot. Aim your cock like you aim your Glock! - And remember to flush!