Jackwack
A clean version for those jackass fuckers that drive you nuts to the point of road rage but you dare not call them that because virgin ears are sitting in the back seat
son of a...stupid jackwack! Get off the road!!
jackwacker
A person who sucks at life. They are incapable of performing basic and simple daily tasks (with the exception of masturbation).
You have your left turn signal on and are clearly trying to merge into the left lane; instead of slowing down to allow you to change lanes, the Jackwacker behind you speeds up to block your access. This guy is a complete Jackwacker; he sucks at life.