infrared

adjective

in·​fra·​red ˌin-frə-ˈred How to pronounce infrared (audio)
-(ˌ)frä-,
-fə-
1
: situated outside the visible spectrum at its red end
used of radiation having a wavelength between about 700 nanometers and 1 millimeter
2
: relating to, producing, or employing infrared radiation
infrared therapy
3
: sensitive to infrared radiation
infrared sensors that detect body heat
infrared noun

Examples of infrared in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The idea is that once the missile has been sighted, the laser counters it with a multi-spectral infrared laser that's powerful enough to dazzle and even destroy the missile's sensors. New Atlas, 20 July 2025 Combined with timelapse recording capabilities, Roman will help researchers to better understand exoplanets, infrared astrophysics, and the nature of dark matter. Andrew Paul, Popular Science, 17 July 2025 Only a short distance away on the same peak is the Gemini South telescope, which also looks at the stars in both visible and infrared wavelengths. Kenna Hughes-Castleberry, Space.com, 14 July 2025 Radio wave wavelengths are much longer than infrared, so beamforming is more difficult. Meghie Rodrigues, IEEE Spectrum, 12 July 2025 See All Example Sentences for infrared

Word History

First Known Use

1881, in the meaning defined at sense 1

Time Traveler
The first known use of infrared was in 1881

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Cite this Entry

“Infrared.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/infrared. Accessed 25 Jul. 2025.

Kids Definition

infrared

adjective
in·​fra·​red ˌin-frə-ˈred How to pronounce infrared (audio)
-(ˌ)frä-
: being, relating to, producing, or using rays like light but lying outside the visible spectrum at its red end
infrared radiation
infrared noun

Medical Definition

infrared

1 of 2 adjective
in·​fra·​red ˌin-frə-ˈred How to pronounce infrared (audio)
1
: lying outside the visible spectrum at its red end
used of radiation having a wavelength between about 700 nanometers and 1 millimeter
2
: relating to, producing, or employing infrared radiation
infrared therapy

infrared

2 of 2 noun
: infrared radiation

More from Merriam-Webster on infrared

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