Snapping hip is a condition in which you feel a snapping sensation or hear a popping sound in your hip when you walk, get up from a chair, or swing your leg around.
The snapping sensation occurs when a muscle or tendon (the strong tissue that connects muscle to bone) moves over a bony protrusion in your hip.
Although snapping hip is usually painless and harmless, the sensation can be annoying. In some cases, snapping hip leads to bursitis, a painful swelling of the fluid-filled sacs that cushion the hip joint.
Read more about snapping hip from AAOS here: http://www.orthoinfo.org/topic.cfm?topic=A00363