to break with a sudden, sharp sound:to crack walnuts. to strike and thereby make a sharp noise:The boxer cracked his opponent on the jaw. to induce or cause to be stricken with sorrow or emotion; affect deeply. to utter or tell:to crack jokes. ...
A Popping Sound When a joint is stretched, the space between the bones increases and the pressure in the synovial fluid decreases. The reduced pressure causes tiny bubbles of gas to develop in the fluid. These bubbles fuse to form larger ones. As new fluid is released into the space from ...