noun: (aviation, military) A system used to quickly decelerate a landing aircraft, essential for landing on an aircraft carrier (although land-based airfields can also be equipped with arresting gear); the most common system consists of a series of transverse wire ropes designed to snag an aircraft's tailhook, connected to a hydraulic or mechanical energy-absorbing system, but other systems exist (typically only for use in an emergency situation) which use a net to slow down an aircraft.
