ul·​tra·​vi·​o·​let | \ˌəl-trə-ˈvī-(ə-)lət \

Definition of ultraviolet 

1 : situated beyond the visible spectrum at its violet end used of radiation having a wavelength shorter than wavelengths of visible light and longer than those of X-rays

2 : relating to, producing, or employing ultraviolet radiation

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Other Words from ultraviolet

ultraviolet noun

Examples of ultraviolet in a Sentence

Recent Examples on the Web

Its Aladin instrument includes a laser that generates pulses of ultraviolet light, which are beamed down into the atmosphere to profile the world's winds. Eric Berger, Ars Technica, "Rocket Report: China aims for the Moon, SpaceX gets approval for load-and-go," 17 Aug. 2018 According to Mayo Clinic, basal cell carcinoma is a type of skin cancer that is thought to be caused by long-term exposure to ultraviolet radiation from sunlight. Temi Adebowale, Good Housekeeping, "Melanie Griffith Makes Plea to Fans After Revealing "Final Stage" to Remove Skin Cancer," 27 Aug. 2018 The orbiter’s main spectrometer, NOMAD, operates in the infrared, ultraviolet and visible parts of the electromagnetic spectrum. Nisha Gaind, Scientific American, "Mars Probe Poised to Solve Red Planet’s Methane Mystery," 26 Apr. 2018 The key components to this new method of detection are an ordinary smartphone, some special software downloaded onto the phone, a box made from Lego bricks, ultraviolet light, a standard 96-well test plate– and a special sauce, so to speak. Allison Barrie, Fox News, "Innovative project harnesses Legos and smartphones in the fight against invisible, deadly weapons," 13 July 2018 Free radicals are created by environmental pollutants and ultraviolet radiation. Talia Abbas, SELF, "I Had a Dermatologist Critique My Skin-Care Routine—and Here's What I'm Changing," 20 June 2018 Methane is also quickly broken down by ultraviolet radiation, so any of the gas discovered on Mars was probably released recently. Adam Mann, Scientific American, "Curiosity Rover Uncovers Long-Sought Organic Materials on Martian Surface," 7 June 2018 Because ultraviolet radiation and oxidizing compounds in the martian soil would destroy any compounds exposed at the surface, Curiosity's scientists used a robotic drill to penetrate several centimeters into the mudstone. Paul Voosen, Science | AAAS, "NASA rover hits organic pay dirt on Mars," 7 June 2018 Meanwhile, stricter approval standards in the U.S. have brought innovation to a standstill and limited options to defend against the sun's harmful ultraviolet radiation. Jack Kaskey, chicagotribune.com, "Your outdated sunscreen exposes you to needless cancer risk," 30 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ultraviolet.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of ultraviolet

1840, in the meaning defined at sense 1

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Last Updated

6 Dec 2018

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The first known use of ultraviolet was in 1840

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English Language Learners Definition of ultraviolet

—used to describe rays of light that cannot be seen and that are slightly shorter than the rays of violet light


ul·​tra·​vi·​o·​let | \ˌəl-trə-ˈvī-ə-lət \

Kids Definition of ultraviolet

: relating to, producing, or being energy that is like light but has a slightly shorter wavelength and lies beyond the violet end of the spectrum


ul·​tra·​vi·​o·​let | \ˌəl-trə-ˈvī-(ə-)lət \

Medical Definition of ultraviolet 

(Entry 1 of 2)

1 : situated beyond the visible spectrum at its violet end used of radiation having a wavelength shorter than wavelengths of visible light and longer than those of X-rays

2 : relating to, producing, or employing ultraviolet radiation



Medical Definition of ultraviolet (Entry 2 of 2)

: ultraviolet radiation

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More from Merriam-Webster on ultraviolet

Rhyming Dictionary: Words that rhyme with ultraviolet

Spanish Central: Translation of ultraviolet

Nglish: Translation of ultraviolet for Spanish Speakers

Comments on ultraviolet

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to enclose within walls

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