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

Only one — but the light bulb has to really want to change. — Tomas Chamorro-Premuzic, Forbes.com, 19 June 2026

According to designers, one of the biggest errors is choosing the wrong light bulb. — Natasha Bazika, Martha Stewart, 14 June 2026

One of my favorite all-time estate sale finds was a huge box filled with a variety of light bulbs for $5. — Jennifer Prince, Southern Living, 5 June 2026

Not every world-changing invention arrives with the fame of the light bulb or the airplane. — Kaif Shaikh, Interesting Engineering, 28 May 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