infrared

adjective in·fra·red \ ˌin-frə-ˈred , -(ˌ)frä- , -fə- \

Definition of infrared

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

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infrared

noun

See infrared defined for English-language learners

See infrared defined for kids

Recent Examples of infrared from the Web

To ensure the driver fixates on the road, an infrared camera mounted on the steering column tracks the eyes.

— mike colias, WSJ, "Self-Driving Dilemma: How to Pass the Wheel Between Human and Robot," 1 Oct. 2017
Although similar in size to Hubble, the WFIRST telescope's infrared instrument would have a field of view that is 100 times greater than the Hubble, allowing it to observe much more of the sky in less time.

— eric berger, Ars Technica, "NASA’s next flagship telescope is “not executable” in its current form," 27 Nov. 2017
These techniques include infrared analysis, 3D modeling, and a technique known as muon detection, which relies on tiny particles created from the collision of cosmic radiation and atmospheric particles.

— maya wei-haas, Smithsonian, "How Researchers Uncovered a Massive Void In The Great Pyramid of Giza," 3 Nov. 2017
Last year the same team used muon detection and infrared measurements to image some kind of corridor right above the entrance to the pyramid.

— maggie fox, NBC News, "Cosmic Rays Reveal Big ‘Void’ in Great Pyramid," 2 Nov. 2017
Harlocker miniaturized them, painted them red, and gave them infrared night vision and thermal-imaging capabilities.

— brian raftery, WIRED, "The Replicant: Inside the Dark Future of Blade Runner 2049," 22 Sep. 2017
Tom says: Going to bed in pajamas made of far infrared (FIR) technology can improve sleep and recovery.

— Health.com, "Tom Brady Versus Gwyneth Paltrow: Whose Wellness Advice Is More Bonkers?," 2 Nov. 2017
Among other unique and highly touted features, the iPhone X model dispenses with Apple’s fingerprint recognition system for unlocking the phone in favor of a cutting-edge infrared facial recognition scanner.

— aaron pressman, Fortune, "Apple Issues Rare Denial of Report on Slipping Standards for Face ID Feature on iPhone X," 25 Oct. 2017
The micro-robot weighs a little more than a pound and can see in complete darkness with its automatic infrared optics.

— jane ford-stewart, Milwaukee Journal Sentinel, "Stealth robo-cop to give eyes and ears to West Allis police facing danger," 4 Oct. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'infrared.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of infrared

1881

in the meaning defined at sense 1

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INFRARED Defined for English Language Learners

infrared

adjective

Definition of infrared for English Language Learners

: producing or using rays of light that cannot be seen and that are longer than rays that produce red light

INFRARED Defined for Kids

infrared

adjective in·fra·red \ ˌin-frə-ˈred \

Definition of infrared for Students

: being, relating to, or producing rays like light but lying outside the visible spectrum at its red end

Medical Dictionary

infrared

adjective in·fra·red \ ˌin-frə-ˈred \

medical Definition of infrared

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

noun

medical Definition of infrared

: infrared radiation

Learn More about infrared

See words that rhyme with infrared Spanish Central: Translation of infrared Nglish: Translation of infrared for Spanish speakers

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infrared

Definition of infrared

infrared

Recent Examples of infrared from the Web

First Known Use of infrared

INFRARED Defined for English Language Learners

infrared

Definition of infrared for English Language Learners

INFRARED Defined for Kids

infrared

Definition of infrared for Students

Medical Dictionary

infrared

medical Definition of infrared

infrared

medical Definition of infrared

Learn More about infrared

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