ul ‧ tra ‧ vi ‧ o ‧ let /ˌʌltrəˈvaɪələt◂, ˌʌltrəˈvaɪəlɪt◂/ BrE AmE adjective ( abbreviation UV )
ultraviolet light cannot be seen by people, but is responsible for making your skin darker when you are in the sun
ultraviolet radiation/rays
ultraviolet radiation from the sun