Definition

(pl. spectra). A series of IMAGES formed when a BEAM of RADIANT ENERGY is separated into its various WAVE LENGTH components, as when a BEAM of white light is refracted and dispersed by a prism. The entire RANGE of electromagnetic RADIATIONS, or any part of it used for a specific purpose, as the RADIO SPECTRUM (10 kilohertz to 300,000 MEGAHERTZ).