blue light

American  

[bloo lahyt] / ˈblu ˈlaɪt /

noun

1. 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.

2. 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.

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Etymology

Origin of blue light

First recorded in 1810–15

Example Sentences

See Examples For:

blue light

After identifying the neurons responsible for the response, they genetically modified those cells so they could be activated with blue light.

From Science Daily ● Jul. 14, 2026

Simply shining blue light onto the mice triggered the same scratching behavior seen during mechanical stimulation, providing strong evidence that these neurons directly produce the itch sensation.

From Science Daily ● Jul. 14, 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

I looked out across the flat, dusty land and could see the slow glow of blue light over the horizon, the first sign of dawn.

From "The Night Diary" by Veera Hiranandani