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

Pair those with a different rug or warmer light bulbs and the room reads as updated even though the biggest piece in it has not moved. — Lauren Jarvis-Gibson, Charlotte Observer, 23 Oct. 2026

Jennifer Jones, the principal designer of Niche Interiors, says living rooms are ideally outfitted with warm light bulbs in the 2,700-3,000 K range. — Maria Sabella, The Spruce, 20 Oct. 2026

The first jerseys of the local soccer team featured a light-bulb emblem, and graffiti light bulbs are still spray-painted on the city’s underpass walls. — Gideon Lewis-Kraus, New Yorker, 19 Oct. 2026

Approximately 17,000 electric light bulbs were used in the theater. — Adam Harrington, CBS News, 16 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