Infrared Light

Infrared (IR) radiation is  electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves. The name means "below red" (from the Latin infra, "below"), red being the color of visible light with the longest wavelength. Infrared radiation has wavelengths between about 750 nm and 1 mm, spanning five orders of magnitude.
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Infrared /in·fra·red/ denoting electromagnetic radiation of wavelength greater than that of the red end of the spectrum, having wavelengths of 0. [more]Infrared light - Community and Resources

Noun
1. electromagnetic radiation with wavelengths longer than visible light but shorter than radio waves
(synonym) infrared, infrared radiation, infrared emission
(hypernym) actinic radiation, actinic ray

Electromagnetic Waves with a Wavelength of 1 millimeter to 700 nanometers.