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

Keep Light Bulbs From Sticking Outdoor light bulbs can have a knack for sticking in the socket after long periods of time, leaving you with the task of trying to unscrew a stubborn bulb without breaking the glass. —Kaitlyn Yarborough, Southern Living, 4 Apr. 2025

Every light bulb has been removed, whether by looters or by soldiers. —New York Times, 22 Mar. 2025

After watching hearings of a chief usher of the White House testifying before Congress during the Clinton administration and describing the White House rooms, Davies had a light bulb moment to bring the Clue board game to life. —Lexy Perez, The Hollywood Reporter, 21 Mar. 2025

Wireless light bulb Rechargeable light bulbs are an easy alternative to traditional bulbs. —Cody Godwin, USA TODAY, 21 Mar. 2025

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