A spectrum is a broad range of similar things or qualities, like the wide spectrum of political beliefs in this country, ranging anywhere from super conservative to über-liberal and everything in between.

Our modern definition of spectrum started out in the 1600s, when scientists used it to refer to the band of colors formed by a beam of light, like a rainbow. In physics, it’s a word that describes the distribution of something, like energy or atomic particles. We still use those scientific meanings today, but spectrum can also apply to non-science related groupings or ranges of related things.

Definitions of spectrum

n a broad range of related objects, values, qualities, ideas, or activities

Type of:
ambit, compass, orbit, range, reach, scope
an area in which something acts or operates or has power or control: "the range of a supersonic jet"

n an ordered array of the components of an emission or wave

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absorption spectrum
the spectrum of electromagnetic radiation that has passed through a medium that absorbed radiation of certain wavelengths
action spectrum
the efficiency with which electromagnetic radiation produces a photochemical reaction plotted as a function of the wavelength of the radiation
atomic spectrum
(physics) a spectrum of radiation caused by electron transitions within an atom; the series of spectrum lines is characteristic of the element
electromagnetic spectrum
the entire frequency range of electromagnetic waves
emission spectrum
spectrum of electromagnetic radiation emitted by a self-luminous source
infrared spectrum
the spectrum of infrared radiation
line spectrum
a spectrum in which energy is concentrated at particular wavelengths; produced by excited atoms and ions as they fall back to a lower energy level
mass spectrum
a distribution of ions as shown by a mass spectrograph or a mass spectrometer
microwave spectrum
the part of the electromagnetic spectrum corresponding to microwaves
radio spectrum, radio-frequency spectrum
the entire spectrum of electromagnetic frequencies used for communications; includes frequencies used for radio and radar and television
acoustic spectrum, sound spectrum
the distribution of energy as a function of frequency for a particular sound source
ultraviolet spectrum
the spectrum of ultraviolet radiation
color spectrum, visible spectrum
the distribution of colors produced when light is dispersed by a prism
speech spectrum
the average sound spectrum for the human voice
Type of:
an orderly arrangement

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