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

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Example Sentences

See Examples For:

blue light

Certain cells that initially detect blue light appear to change into cells sensitive to red and green light, helping create the specialized arrangement needed for clear central vision.

From Science Daily ● Oct. 31, 2026

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

Young said she noticed it when the Ring camera’s blue light would turn on, signaling recording was happening, at times when she and her family members had not press record.

From Los Angeles Times ● Jun. 25, 2026

Mindless scrolling might seem appealing, but the blue light from the screen can stimulate your brain and leave you feeling more awake.

From BBC ● Jun. 22, 2026

Seeing my precautions in the cool blue light of early morning, I was a little embarrassed.

From "The Name of the Wind" by Patrick Rothfuss

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