Illustration of light bulb
- 1 bulb containing gas
- 2 filament
- 3 connecting and supporting wires
- 4 exhaust tube
- 5 screw base
- 6 base contact
light bulb
noun
variants
or lightbulb
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
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
See All Example Sentences for light bulb
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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
See All Example Sentences for light bulb
Cite this Entry
“Light bulb.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/light%20bulb. Accessed 19 Jun. 2025.
Copy CitationKids 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
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