Spectrum 2
Spectrum 2 : (1) (Opt) Electromagnetic radiation separated into its constituents by a prism, grating, or other means and displayed as an array of frequencies or wavelengths. (2) (Spectr) A visual display, a photographic record, or a plot of the distribution of the intensity of a given type of radiation as a function of its wave length, energy, frequency, momentum, mass, or any related quantity