ul·tra·vi·o·let (ŭl′trə-vīə-lĭt, -vīlĭt)
adj. Abbr. UV
1. Of or relating to electromagnetic radiation between violet visible light and x-rays in the electromagnetic spectrum, having frequencies between 790 terahertz and 30 petahertz and wavelengths between 380 nanometers and 10 nanometers.
2. Of or relating to a light bulb that emits ultraviolet radiation.
The ultraviolet range of electromagnetic radiation: Sunburns result from radiation in the ultraviolet.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.