radar trap noun1 •A roadside location, manned by police or similar officials, where a device that emits a radar beam is used to monitor the speeds of motor vehicles in order to apprehend motorists in violation of the speed limit.In Rochester, after Kenneth Butters complained about fast driving along Woodbine Avenue, police set up a radar trap and nabbed five speeders, including Butters. — 1956 formsradar traps
