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

Quick and Painless Unlike traditional saunas, which can take a long time to preheat, this infrared model is quick and painless. —Parker Hall, WIRED, 11 Dec. 2024

Antimony is used in solar cells and increasingly in defense technology like infrared missiles and nuclear weapons and as a hardening agent for bullets and tanks. —Joseph Epstein, Newsweek, 10 Dec. 2024

Ideal for budget-conscious streamers, this model provides access to a wide range of popular streaming apps, though its basic infrared remote requires line-of-sight and lacks voice control. —Shubham Yewale, PCMAG, 3 Dec. 2024

The idea is that the visible and infrared cameras can make a visual identification of the intruder while the eye-harmless laser provides information about distance and altitude to help with analysis. —David Szondy, New Atlas, 25 Nov. 2024

Word History

First Known Use

1881, in the meaning defined at sense 1

Phrases Containing infrared

• far-infrared
• near-infrared

Kids 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