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 image was captured Jan. 8 by Maxar Technologies' shortwave infrared sensor. —Ramon Padilla, USA TODAY, 9 Jan. 2025

Dell 32 Plus 4K QD-OLED monitor Photo by Antonio G. Di Benedetto / The Verge Dell’s new 32-inch 4K OLED display uses an infrared sensor and five speakers located below the screen to track your head and beam sound directly to your ears. —Andrew Liszewski, The Verge, 7 Jan. 2025

Their detection was made possible by JWST's sensitivity to infrared light. —Jamie Carter, Forbes, 6 Jan. 2025

As the sheriff's department's homicide bureau and missing persons unit were notified, the deputies who arrived at the scene quickly deployed a drone, or an unmanned aircraft system (UAS), equipped with infrared technology to scour the area from the sky, the sheriff's department said. —Bill Hutchinson, ABC News, 26 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