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

The 35-pound Javelin ranges as far as 2.5 miles under infrared guidance. —David Axe, Forbes, 5 Nov. 2024

There’s also a front-facing speaker and a tiny working infrared remote control. —Simon Hill, WIRED, 4 Nov. 2024

The researchers used advanced techniques, including gas chromatography and Fourier transform infrared spectroscopy, to determine what the tunic was made from. —Marco Rubio, Newsweek, 1 Nov. 2024

Plastics, specifically, have special attributes in the shortwave infrared (SWIR) electromagnetic spectrum that aren’t present in sand or other organic debris. —Mack Degeurin, Popular Science, 30 Oct. 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