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ultraviolet

American  
[uhl-truh-vahy-uh-lit] / ˌʌl trəˈvaɪ ə lɪt /

adjective

  1. beyond the violet in the spectrum, corresponding to light having wavelengths shorter than 4000 angstrom units.

  2. pertaining to, producing, or utilizing light having such wavelengths.

    an ultraviolet lamp.

noun

  1. ultraviolet radiation.

ultraviolet British  
/ ˌʌltrəˈvaɪəlɪt /

noun

  1. the part of the electromagnetic spectrum with wavelengths shorter than light but longer than X-rays; in the range 0.4 × 10 –6 and 1 × 10 –8 metres

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

adjective

  1.  UV.  of, relating to, or consisting of radiation lying in the ultraviolet

    ultraviolet radiation
"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
ultraviolet Scientific  
/ ŭl′trə-vī′ə-lĭt /

  1. Relating to electromagnetic radiation having frequencies higher than those of visible light but lower than those of x-rays, approximately 10 15 –10 16 hertz. Some animals, such as bees, are capable of seeing ultraviolet radiation invisible to the human eye.

  2. See more at electromagnetic spectrum

  1. Ultraviolet light or the ultraviolet part of the spectrum.

  2. See Note at infrared

Etymology

Origin of ultraviolet

First recorded in 1870–75; ultra- + violet

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

They found that galaxies within about a million light-years of the quasar showed weaker O III emissions compared to their ultraviolet light.

From Science Daily • Mar. 30, 2026

Analysts predict future logic and memory chips will require increased use of ASML’s extreme ultraviolet lithography tools.

From Barron's • Mar. 20, 2026

A light source with a very tight wavelength, somewhere between ultraviolet light and X-rays, shines through a chip-shaped stencil and onto the silicon wafer.

From The Wall Street Journal • Feb. 27, 2026

Around him were additional signs of disrepair: an X-ray examination board without a functioning backlight, and a dust-covered ultraviolet sterilization machine that hadn’t worked in months.

From Los Angeles Times • Feb. 13, 2026

If we had used ultraviolet light—simulating the early Sun—the results would have been more or less the same.

From "Cosmos" by Carl Sagan

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.