So what is a chop anyway? It’s not a meat product I can tell you that . . . mmmmm, pork chop (with applesauce, of course).
The expression actually goes even further back . . . in the 16th century, ‘chops’ was used to describe one’s jaws, mouth and parts of the mouth.
You know . . . as in licking your chops after eating a particularly succulent piece of steak as the juices run down your chin. Yeah, like that.
So, literally, busting chops would be like punching someone in the mouth or whacking someone upside the head. Of course now it’s more metaphorical . . . not an actual smack across the ol’ choppers.