When engaging in intercourse with a woman from behind in the vagina, a quick, sudden and forceful penetration of the anus. Often occuring as an accident, it may also occur as a "How do you do!" to simply ring her bell.
Last time I was bangin'-it-in with that bitch, I gave her a donkey punch, so to spice things up, I gave her the ole' Arkansas knuckleball!
A car usually driven by a senior citizen. From behind all you can see is the top of their head and their knuckles on the steering wheel. This vehicle is usually driving very slow and sometimes looks like no one is behind the wheel.
Dude, I'm gonna be late for work because I can't get around this knucklewagon.