infrared radiation

Cultural

Invisible radiation in the part of the electromagnetic spectrum characterized by wavelengths just longer than those of ordinary visible red light and shorter than those of microwaves or radio waves. (Compare ultraviolet radiation.)

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The heat we feel from a glowing coal or an incandescent light bulb is from infrared rays.

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The star also shows an excess of infrared radiation, which is often linked to disks of material around young stars.

From Science Daily • Jan. 24, 2026

These glasses reduce visible sunlight to safe and comfortable levels and block all but a tiny fraction of solar UV and infrared radiation, according to the American Astronomical Society.

From Los Angeles Times • Apr. 4, 2024

Like any hot object, it was giving off radiant heat -- what we’d now call long-wave infrared radiation.

From Scientific American • Nov. 9, 2023

Germanium is mainly used in fibre optics and plastics as well as infrared radiation.

From Reuters • Jul. 4, 2023

Rattlesnakes and doped semiconductors detect infrared radiation perfectly well.

From "Cosmos" by Carl Sagan

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023