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

Each spacecraft’s plutonium core produces a little less juice each year, however—annually losing about four watts, equivalent to a low-power light bulb. —Meghan Bartels, Scientific American, 6 Mar. 2025

Thomas Edison’s electric light bulb and power distribution systems and Nikola Tesla’s alternating current innovations relied on copper’s conductivity and corrosion resistance, enabling widespread electrification. —Ed MacHa, Forbes, 5 Mar. 2025

How about a small light bulb that has 16 million colors? —Ho Lin, Miami Herald, 3 Mar. 2025

Trump previously criticized energy efficient light bulbs and low-flow toilets. —Elizabeth Weise, USA TODAY, 12 Feb. 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