light bulb

noun

variants or lightbulb

ˈlīt-ˌbəlb 

plural light bulbs or lightbulbs

: an electric lamp: such as

a

: one in which a filament gives off light when heated to incandescence by an electric current

called also incandescent, incandescent lamp

b

: one having a coating of fluorescent material on its inner surface that emits visible light : fluorescent lamp

especially : compact fluorescent light

c

: one using LEDs to generate light

Illustration of light bulb

• 1 bulb containing gas
• 2 filament
• 3 connecting and supporting wires
• 4 exhaust tube
• 5 screw base
• 6 base contact

Examples of light bulb in a Sentence

Recent Examples on the Web

Use a light bulb with a lower wattage to reduce heat exposure. — Karen Brewer Grossman, Southern Living, 5 Nov. 2026

My Alexa voice commands to stream video from the doorbell to an Amazon Echo Show smart display worked perfectly, as did my Alexa routine to have a Tapo L535E light bulb turn red when the doorbell button was pressed. — John R. Delaney, PC Magazine, 3 Nov. 2026

Meanwhile, the light bulbs in our apartment were mysteriously flickering. — Will Tizard, Variety, 1 Nov. 2026

When indoors in the evening, dim the lights and use warm light bulbs rather than overhead and blue lighting. — Randy J. Nelson, Scientific American, 30 Oct. 2026

Word History

First Known Use

1885, in the meaning defined above

Rhymes for light bulb

• lightbulb

Kids Definition

lightbulb

noun

light·​bulb ˈlīt-ˌbəlb 

: an electric lamp: as

a

: one in which a filament gives off light when heated by an electric current

called also incandescent lamp

b

: fluorescent lamp