What is billiards rebound?

There is no such thing as a billiards bounce. A person that does not know the proper terms might call a jump shot, a scoop shot, or a carom a "bounce" but this in incorrect.

The term bounce is not a billiards term, but there are "tricks" where the Word bounce can be used - one such is when racking, placing all the balls except the 8 ball in the rack, and then dropping the 8 ball on the rail to make it "bounce" into the center of the rack.