slap
To have a very loud, good quality sound system esp. in your car. Or a song that just sounds hella good and has tremendous bass in it. I have to set the record str8 once again. We started this in the Town, Oakland, Ca, USA. When everybody else was still callin it "Knock" or "Thump" We in Oakland started calling it "Slap". The rest of the Bay Area eventually caught on to it. Str8 Up!