three-way bulb

three′-way` bulb′

a light bulb that can be switched to three successive degrees of illumination.
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References in periodicals archive ?
Also make certain your three-way bulb is screwed in snugly.
The three-way bulbs that ramp up to the equivalent of a 150-watt incandescent can be either circular or spiral.
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.
* Certain types of incandescent specialty bulbs, including appliance, heavy-duty, colored and three-way bulbs are exempt from the new standards.
CFL flood lamps, reflectors, dimmable bulbs, bug lights, decor globes, candelabras, and three-way bulbs are direct replacements for their incandescent counterparts.
Individual stores may need to adjust to the neighborhood; lower income areas use fewer decorative bulbs and three-way bulbs, for example.
* Three-contact bases are used for three-way bulbs that contain two separate filaments in one bulb.