blue light
Americannoun
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a band of the visible light spectrum that has a shorter wavelength and produces higher energy than other colors of light: occurring in sunlight and emitted by electronic devices that use LED technology.
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American History, Usually Disparaging. Also Blue Light a member of a faction of the American Federalist party considered disloyal for opposing the War of 1812: so called from the claim that they flashed blue light signals to alert the British to the presence of blockade runners.
Etymology
Origin of blue light
First recorded in 1810–15
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.
Using observations of Venus together with radiative-transfer modeling, the scientists estimated how strongly the liquid inside the planet's cloud droplets would need to absorb ultraviolet and blue light to match what spacecraft and telescopes observe.
From Science Daily ● Sep. 13, 2026
A blue light drive to a woman who is having constant seizures.
From BBC ● Jul. 10, 2026
In 2020, Longcore co-published a study linking artificial night light, including blue light emitted by LEDs, to cancer.
From Los Angeles Times ● May 8, 2026
Depending on the situation, a Tesla will gently warn with a message and a flashing blue light on the center screen, buzz, or require pressure on the steering wheel.
From Barron's ● May 3, 2026
It was a shimmering green, growing deeper with the blue light of evening.
From "The House of the Scorpion" by Nancy Farmer
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
