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 intriguing spa menu goes far beyond standard massages, with fascial release therapy, scalp exfoliation, abdominal massage, infrared heated body masks, and a magnesium-laden meridien massage to combat jet lag. —Amber Gibson, Travel + Leisure, 30 Apr. 2025

Heat therapy via infrared saunas has been a part of their wellness routines. —Izzy Baskette, People.com, 6 May 2025

At the same time, the infrared wavelengths improve microcirculation and reduce inflammation in surrounding facial tissue, leading to a noticeable glow and improved skin tone over time. —Julie Loffredi, Forbes.com, 5 May 2025

In 2006, the Japanese Aerospace Exploration Agency launched the infrared satellite AKARI, which was active until 2011. —Julia Jacobo, ABC News, 2 May 2025

Word History

First Known Use

1881, in the meaning defined at sense 1

Phrases Containing infrared

• far-infrared
• near-infrared

Rhymes for infrared

• abovesaid
• aforesaid
• arrowhead
• casinghead
• copperhead
• figurehead
• fountainhead
• gingerbread
• hammerhead
• leatherhead
• letterhead
• loggerhead

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