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