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
ultraviolet noun

Examples of ultraviolet in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The layer plays a vital role in absorbing the sun’s ultraviolet radiation, which can cause diseases such as skin cancer. Adam Kovac, Scientific American, 16 Sep. 2026 The final step is ultraviolet disinfection, which uses high-intensity ultraviolet light to kill or inactivate viruses and parasites, such as giardia. Piper Heath, Los Angeles Times, 16 Sep. 2026 Wade knew that despite their apparent uniformity, oceans hide many distinct habitats that differ in temperature, currents, ultraviolet light, chemistry, and oxygen. Quanta Magazine, 11 Sep. 2026 Since low-energy X-rays and ultraviolet light are next to each other on the electromagnetic spectrum, Muhibullah and his team suspect that the low-energy X-rays are spillover from objects emitting prodigious amounts of ultraviolet. Keith Cooper, Space.com, 11 Sep. 2026 See All Example Sentences for ultraviolet

Word History

First Known Use

1840, in the meaning defined at sense 1

Time Traveler
The first known use of ultraviolet was in 1840

Browse Nearby Words

Cite this Entry

“Ultraviolet.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ultraviolet. Accessed 19 Sep. 2026.

Kids Definition

ultraviolet

adjective
1
: located beyond the visible spectrum at its violet end and having a wavelength shorter than those of visible light but longer than those of X-rays
2
: relating to, producing, or using ultraviolet radiation
ultraviolet noun

Medical Definition

ultraviolet

1 of 2 adjective
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

ultraviolet

2 of 2 noun
: ultraviolet radiation
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