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

In addition to selecting the right fixtures and light bulbs, Lerner says their placement within the bathroom matters as well. —Maria Sabella, Better Homes & Gardens, 14 Apr. 2025

Tens of thousands of customers around the country already get everything from lunchtime goodies and replacement light bulbs to vaccines and prescriptions via drone. —Seth Jacobson, USA TODAY, 19 Mar. 2025

Now the light bulb section at the hardware store has become so daunting that even bringing the empty box from the last bulbs doesn’t help. —Inga, San Diego Union-Tribune, 17 Feb. 2025

Is there any truth to the claims that yellow light bulbs keep insects away? —Brandee Gruener, Southern Living, 17 Apr. 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