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 X-ray data from Chandra reveal the young stars within the cluster in red, while the infrared data from Webb show clouds of dust in orange, yellow, green, and blue. —Stefanie Waldek, Space.com, 19 Dec. 2024

The couple chose an area near RiNo at 3004 Downing St. to create a relaxing space with beer baths, an infrared sauna, zero-gravity massage chairs, and a craft beer taproom. —Sara Hansen, The Denver Post, 19 Dec. 2024

The bottom edge has a slightly wider gray bezel bearing the Fire TV logo in the center with a flat, blocky extension holding an infrared sensor, far-field microphones, and a mic mute switch below it. —PCMAG, 17 Dec. 2024

Effective systems combine radar, radio frequency, acoustic detection, and infrared sensors. —Hannah Parry, Newsweek, 17 Dec. 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