wigwag

Any of a number of mechanical or electrical devices which cause a component to oscillate between two states.

A device that causes one or more lights to flash in a preset pattern.

A red light near the door of a sound stage that flashes to indicate that cameras are rolling inside the stage and that all people and vehicles outside should remain quiet; a red-eye.

A device used to cause lamps installed on a motor vehicle, especially an emergency vehicle such as an ambulance or police car, to flash as a warning.

A device with multiple (often two), alternately flashing lights which is installed at a railway level crossing (or grade crossing), a movable bridge, etc., to warn vehicular traffic to stop.

An instrument that creates a wigwagging motion for polishing.

A warning device inside the cabin of a truck that causes a mechanical arm to drop into view when the pressure in the airbrake system of the truck becomes too low for the brakes to be reliably deployed.

(US) A grade crossing signal with a swinging motion used to indicate an approaching train.

(US, historical) A signal sent by waving a flag to and fro.

To move gently in one direction and then another; to wig or wiggle, to wag or waggle.

To oscillate between two states.

(US, historical) To send a signal by waving a flag to and fro.

An act of wigwagging.

With a wigwagging or to-and-fro motion.