light bulb

American

noun

an electric light.

light bulb British

noun

Sometimes shortened to: bulb. a glass bulb containing a gas, such as argon or nitrogen, at low pressure and enclosing a thin metal filament that emits light when an electric current is passed through it

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of light bulb

First recorded in 1880–85

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

From that light bulb moment, Recondition, which Brown said created every piece with accessibility and style in mind, was born.

From BBC • Mar. 24, 2026

In contrast, regulatory bodies like the FTC have been part of the federal government for longer than the light bulb.

From Slate • Dec. 11, 2025

His most recent apartment inspection failed because the light bulb in the fridge was out.

From Slate • Oct. 8, 2025

She’d often mix her mayo with Marconi hot giardiniera relish to make her own sauce, which sparked the light bulb moment.

From Los Angeles Times • Dec. 6, 2024

When I got there, Mr. Loeffler was sitting on his front porch with a light bulb in his hand.

From "Okay for Now" by Gary D. Schmidt

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023