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

Four years ago, Roku went from a streaming business to producing a broader range of smart home gadgets, including security cameras, light bulbs, and smart plugs. — James Peckham, PC Magazine, 12 Nov. 2026

Residents and businesses are also encouraged to take part; even simply changing a light bulb at the entrance of a home or business to a green bulb would show support. — Amanda Greenwood, MSNBC Newsweek, 10 Nov. 2026

Use a light bulb with a lower wattage to reduce heat exposure. — Karen Brewer Grossman, Southern Living, 5 Nov. 2026

Meanwhile, the light bulbs in our apartment were mysteriously flickering. — Will Tizard, Variety, 1 Nov. 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