A range; a continuous, infinite, one-dimensional set, possibly bounded by extremes.

plural of spectrum

(informal) Having an autism spectrum disorder or exhibiting traits pertaining to or within the autism spectrum.

(physics) An electronic device that displays the frequency spectrum of an electrical, optical or acoustic waveform.

(physics) The entire range of wavelengths of all known electromagnetic radiations extending from gamma rays, to X-rays through visible light, infrared, to radio waves.

(physics) The portion of the electromagnetic spectrum that is visible to humans. / (physics) an extension of the human-visible spectrum to include near-visible wavelengths, primarily near infrared.

The colours of the rainbow. / (physics) The distribution of colours produced when white light passes through a prism. / (astronomy, physics) The range of frequencies of visible light.

(physics) The characteristic pattern of dark lines or bands that occurs when electromagnetic radiation is passed through an absorbing medium into a spectroscope.

(physics) The distribution of the intensity of particles or radiation emitted in a nuclear process as a function of energy - a unique signature of each process.

(physics) An absorption or emission spectrum consisting of bands of closely-spaced lines; characteristic of polyatomic molecules.