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

Prosecutors said hospital security camera video showed Mabon wearing a camouflage jacket, the same jacket worn by a suspect seen removing a light bulb from the victim’s neighbor’s porch a few hours before the home-invasion robbery was committed. —Rosalio Ahumada, Sacbee.com, 9 Oct. 2025

Advertisement For Koh, the paper set off a light bulb. —Alice Park, Time, 30 Sep. 2025

Edison’s first fragile light bulbs were just one early step in the electric revolution that has helped create today’s richly illuminated world. —Ernest Freeberg, The Conversation, 29 Sep. 2025

This was Wickelgren’s light bulb. —Joseph Howlett, Quanta Magazine, 26 Sep. 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