/ul'treuh vuy"euh lit/ , adj.
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. Cf. infrared .
n.
3. ultraviolet radiation.
[ 1870-75; ULTRA- + VIOLET ]