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

The program provides basic repair services for issues such as leaky faucets, light switches, or even just changing a light bulb. — Steve Metsch, Chicago Tribune, 14 Aug. 2026

Villasana notes that smart light bulbs, specifically, were her favorite dorm room purchase. — Natalia Gonzalez Blanco Serrano, The Spruce, 27 July 2026

Back healthy and carrying the subtle confidence of a player whose NFL light bulb appeared to turn on, Harrison worked with the first-team unit on a deep Falcons defensive line in the early part of summer practices. — Daniel Flick, AJC.com, 20 July 2026

The difference is not much—the equivalent of removing one light bulb from a board of 10,000 of them—but that’s enough for sensitive telescopes to detect. — Jeffrey Kluger, Time, 16 July 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