infrared
adjective
in·fra·red
ˌin-frə-ˈred 
-(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
Even the 27,000-square-foot spa, which has cryotherapy treatments, IV drips, and an infrared sauna, houses a Wave Table, which claims to provide the equivalent of three hours of sleep in 30 minutes.
—
Alisha Prakash, Travel + Leisure, 14 June 2025
It’s made from beryllium and made-up of 18 hexagonal segments, each one covered in a super-thin layer of gold that’s perfect for reflecting infrared light.
—Jamie Carter, Forbes.com, 12 June 2025
For lower-mass stars, which shine brightest in infrared, Gaia’s observations were augmented by data from NASA’s Wide-field Infrared Survey Explorer and the Spitzer Space Telescope.
—Phil Plait, Scientific American, 12 June 2025
At the aft, a giant full-beam gym with an infrared sauna opens onto a beach club with a Jacuzzi, folding terraces, and stairs that lead to the water.
—Rachel Cormack, Robb Report, 11 June 2025
See All Example Sentences for infrared
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Alisha Prakash, Travel + Leisure, 14 June 2025
It’s made from beryllium and made-up of 18 hexagonal segments, each one covered in a super-thin layer of gold that’s perfect for reflecting infrared light.
—Jamie Carter, Forbes.com, 12 June 2025
For lower-mass stars, which shine brightest in infrared, Gaia’s observations were augmented by data from NASA’s Wide-field Infrared Survey Explorer and the Spitzer Space Telescope.
—Phil Plait, Scientific American, 12 June 2025
At the aft, a giant full-beam gym with an infrared sauna opens onto a beach club with a Jacuzzi, folding terraces, and stairs that lead to the water.
—Rachel Cormack, Robb Report, 11 June 2025
See All Example Sentences for infrared
Cite this Entry
“Infrared.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/infrared. Accessed 18 Jun. 2025.
Copy CitationKids Definition
infrared
adjective
in·fra·red
ˌin-frə-ˈred
-(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
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
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