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.
Officials also utilized a specialized drone with infrared technology and are awaiting results. Jenna Sundel, MSNBC Newsweek, 8 Oct. 2025 As per Peña-Mora, robotics is also advancing bridge inspection, using techniques like infrared imaging, LiDAR, and crack detection to collect data autonomously. Georgina Jedikovska, Interesting Engineering, 7 Oct. 2025 An infrared camera documents both its escape and our arrival. Ganesh Marín, The Dial, 7 Oct. 2025 Between the first 10 hours and three days after birth, the team observed how the newborns’ brains reacted to German, Hebrew and French by using functional near-infrared spectroscopy (fNIRS), a noninvasive imaging technique that measures changes in blood oxygenation in the brain. Meghie Rodrigues, Scientific American, 7 Oct. 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 10 Oct. 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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