A band or range of frequencies; the audible spectrum runs from 20 Hz to 20,000 Hz (20 kHz). The spectrum is simply a term to describe a group of frequencies. There are a variety of different spectrums that are generally accepted as standards (such as the audible spectrum and visual spectrum). Spectrum can also refer to any specific band of frequencies such as the spectrum from 1,000 Hz to 1,200 Hz. Spectrum can also be called band.