UVB Definition

yo͝ovēbē
noun
Ultraviolet light with a shorter wavelength than UVA and thus closer in size to X-rays.
Webster's New World

Origin of UVB

  • u(ltra)v(iolet) B (the letter B being used to designate the second of the categories based on wavelength in which ultraviolet radiation is classified)

    From American Heritage Dictionary of the English Language, 5th Edition