A threatening term implied to mean an ass-kicking, but left open ended to sound more ominous.
Example 1: "He betta watch his ass or ima bust some chops!"
Example 2:
Guy 1: "That old bastard just cut me off!"
Guy 2: "Thats it, let's go bust his chops"
When you are a small time drug dealer and have to make sales on foot.....
person 1: what are you up to tonight?
person 2: Oh so and so called me I have to go bust some chops.