The act of hitting someone with a bit more force then a thwap. Generally applied when someone needs a sharp enough blow to make them take notice but not to cause actual lasting pain. Usually directed toward one that the striker has affection for as minor punishment.
"My friend was being an ass in front of my sister so I bapped him a good one"
to bump into something. To hit something. to get into a small accident and damage something.
I bapped my car today.