ultraviolet

adjective

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

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

Designed to be entirely clear, the domes would let in sunlight but not harmful ultraviolet rays from the sun, says Robin Wordsworth, an earth and planetary sciences professor at Harvard University and a co-author of the new research. —Claire Cameron, Scientific American, 18 Dec. 2025

If that switch is exposed to ultraviolet light, the adhesive gives out and releases the spring, closing the circuit and allowing an indicator light bulb to illuminate. —New Atlas, 15 Dec. 2025

While the Mars Reconnaissance Orbiter captured one of the closest images of 3I/ATLAS, MAVEN obtained ultraviolet images that NASA said should help scientists understand the comet’s make-up. —Eric Lagatta, USA Today, 12 Dec. 2025

Tanning beds emit 10 to 15 times more ultraviolet A (UVA) rays than the sun. —Emily Kay Votruba, EverydayHealth.com, 12 Dec. 2025

Word History

First Known Use

1840, in the meaning defined at sense 1

Phrases Containing ultraviolet

• far-ultraviolet
• near-ultraviolet

Rhymes for ultraviolet

• inviolate
• violet

Kids Definition

ultraviolet

adjective

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

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

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

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