A maneuver where a male pulls his pants down while in a standing position (generally to the ankles), lifts his shirt with one hand, and expeditiously thrusts his hips back and forth in a swinging motion. If done correctly, the thrusting will swing his "member" into contact with the abdomen on the upswing, and the leg or anus on the downswing, thereby creating a "clacking" sound. It is recommended that this act be augmented by pouring a beer over the crotch with the free hand to accentuate the clacks being generated.
Ross was getting annoyed by Carissa so he decided to pull out The Clacker
to make her leave.