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.
Roman will pair a large field of view with crisp infrared vision to survey deep, vast swaths of sky. — Richard Tribou, The Orlando Sentinel, 29 June 2026 In the moonlight, a team wearing headlamps and infrared goggles gather around a motorcycle engine with a cable that runs to the launching pad. — Joanna Kakissis, NPR, 27 June 2026 Prefab kits and plug-in infrared units have brought entry prices lower than most people expect, though hidden costs like electrical upgrades and ventilation still catch buyers off guard. — Allison Palmer updated June 25, Charlotte Observer, 25 June 2026 Phase-change materials that manage temperature by absorbing or releasing heat, infrared fibers and coatings, and advanced moisture-wicking technologies are also part of this innovation landscape. — Arthur Zaczkiewicz, Footwear News, 30 June 2026 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

Phrases Containing infrared

Rhymes for infrared

See All Rhymes for infrared

Browse Nearby Words

infra praesidia
infrared
infrared lamp
See all Nearby Words

Cite this Entry

“Infrared.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/infrared. Accessed 7 Jul. 2026.

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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

Nglish: Translation of infrared for Spanish Speakers

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