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
Cite this Entry
“Light bulb.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/light%20bulb. Accessed 7 Jul. 2026.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
