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
Over the past century, that display, and symbol of the New Year, has evolved from an iron and wood cage adorned with light bulbs to a dazzling technicolor crystal sphere.
—
Jack Guy, CNN Money, 31 Dec. 2025
Here’s why changing light bulb temperature and lampshades works so well.
—Gemma Johnstone, The Spruce, 31 Dec. 2025
Keep Light Bulbs From Sticking Outdoor light bulbs can have a knack for sticking in the socket after long periods of time, leaving you with the task of trying to unscrew a stubborn bulb without breaking the glass.
—Kaitlyn Yarborough, Southern Living, 25 Dec. 2025
If that switch is exposed to ultraviolet light, the adhesive gives out and releases the spring, closing the circuit and allowing an indicator light bulb to illuminate.
—New Atlas, 15 Dec. 2025
See All Example Sentences for light bulb
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Jack Guy, CNN Money, 31 Dec. 2025
Here’s why changing light bulb temperature and lampshades works so well.
—Gemma Johnstone, The Spruce, 31 Dec. 2025
Keep Light Bulbs From Sticking Outdoor light bulbs can have a knack for sticking in the socket after long periods of time, leaving you with the task of trying to unscrew a stubborn bulb without breaking the glass.
—Kaitlyn Yarborough, Southern Living, 25 Dec. 2025
If that switch is exposed to ultraviolet light, the adhesive gives out and releases the spring, closing the circuit and allowing an indicator light bulb to illuminate.
—New Atlas, 15 Dec. 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 3 Jan. 2026.
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
Love words? Need even more definitions?
Merriam-Webster unabridged
Share