A timepiece provided with a device for registering and indicating the exact time when a watchman visits certain stations on his beat.

(railways) A bar, connected with a switch, longer than the distance between any two consecutive wheels of a train, laid inside a rail and operated by the wheels so that the switch cannot be thrown until the entire train has passed the switch.

plural of detector bar

plural of motion detector

(informal) A supposed innate ability to identify sarcasm.

A device that helps to identify the presence of bats by converting their echolocation ultrasound signals to audible frequencies.

plural of bat detector

plural of detector van

plural of sarcasm detector

plural of window detector