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 50-foot string has 25 shatterproof globe light bulbs that are spaced 2 feet apart. —Maggie Horton, People.com, 10 June 2025

But the light bulb is unwilling to change in L.A., where the city and county governments have refused to enforce a ban on public camping as a matter of principle. —Susan Shelley, Oc Register, 5 June 2025

Speaking of light, the lamp uses a 50-watt halogen light bulb to slowly melt the candle and illuminate their space with gentle, ambient lighting. —Alicia Geigel, Southern Living, 3 June 2025

Chains loosen, light bulbs burn out, and the list goes on. —Josh Max, Forbes.com, 30 May 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