To strike or otherwise beat with or without an implement of beating. Originally started as a parody of the visual 1960s Batman fight sound effects. Imagine the word "PAK" in bright letters when you strike someone or something.
If he doesn't shut up I'm going to pak him in the head.
The posterior of a human being or animal, also anus.
"Bob, for god's sake put away your turd crimper. You're wearing a belt, USE IT!"
Any packaged conglomeration of trash used as a weapon against a motorist. A trashogram may have insults written on it. It is generally thrown at or into the vehicle of an erratic or dangerous driver.
"that ignorant squack just pulled in front of the semi, and cramped on the binders!!"
"here, throw a trashogram in her window"