/,ʌltrə'vaɪələt; ,ʌltrə`vaɪəlɪt/
adj [usu attrib通常作定语]
1 (physics 物) (of radiation) with a wavelengththat is just beyond the violet end of the visible spectrum （指辐射）紫外的
*ultraviolet rays, ie causing sun-tanning 紫外线.
2 of or using such radiation 紫外线的; 利用紫外线的
*an ultraviolet lamp 紫外线灯
* ultraviolet treatment, ie for skin diseases 紫外线疗法（用以治疗皮肤病）. Cf 参看 infra-red (infra).

adj
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