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

When outfitting a space with mood lighting or installing pendant clusters, opt for light bulbs with lower lumens to avoid harsh overhead lighting. —Maria Conti, Better Homes & Gardens, 3 June 2025

Let There Be Light – Students explored the properties of light: how a light bulb contains a rainbow of colors, what happens when a beam of laser light is trapped in water, and more. —Larry D. Urish, Oc Register, 3 June 2025

Thomas Edison: Scale Comes From Standardization Thomas Edison is best known for inventing the light bulb, but his biggest achievement may have been something more strategic: creating the first industrial research lab. —Abdo Riani, Forbes.com, 29 May 2025

In September 2024, the U.S. Department of Defense invested $4.2 million in Rare Earth Salts, a startup that aims to extract the oxides from domestic recycled products such as fluorescent light bulbs. —Evelyn Cheng, CNBC, 28 May 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