three-way bulb

three′-way` bulb′

a light bulb that can be switched to three successive degrees of illumination.
References in periodicals archive ?
We re excited to provide our customers the 3-Way Cree LED Bulb, an affordable LED alternative that delivers on the promise of a real three-way bulb with three distinct and visible levels of light, said Mark Voykovic, light bulb merchant, The Home Depot.
Also make certain your three-way bulb is screwed in snugly.
A whole lot of bulbs are exempt, including three-way bulbs, 150-watt bulbs and bulbs with narrower candelabra bases that are often used in chandeliers.
Individual stores may need to adjust to the neighborhood; lower income areas use fewer decorative bulbs and three-way bulbs, for example.