ul·tra·vi·o·let 
(ŭl′trə-vīə-lĭt)
(ŭl′trə-vīə-lĭt)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.
n.
The ultraviolet range of electromagnetic radiation: Sunburns result from radiation in the ultraviolet.