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noun Uncommon

infrared

ihnf-ruh-REHD

Infrared (noun) means Light energy just beyond the red end of the visible spectrum, felt as heat but invisible to the eye. Example: “Night-vision goggles work by detecting infrared given off by warm bodies.”

noun
1
Light energy just beyond the red end of the visible spectrum, felt as heat but invisible to the eye.
"Night-vision goggles work by detecting infrared given off by warm bodies."
"The remote control sends signals to the TV using infrared."
adj
1
Relating to or using this kind of radiation.
"The camera has an infrared sensor for low-light shots."

How to use infrared

Learner’s notes

In plain EnglishInvisible heat-radiation light, used in remotes, night vision, and heaters.

Easily confused with
Common pairings
infrared camera infrared radiation infrared sensor

Word forms

infrareds plural

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Test yourself on “infrared” A quick quiz — meaning, synonyms & usage

Fill the gap

Can you complete this real example?

Night-vision goggles work by detecting _____ given off by warm bodies.

Etymology

From "infra-" ("below") + "red," describing wavelengths just below visible red light.

thermal radiation

Rhymes for infrared

See all rhymes for infrared →

Frequently asked questions

What does “infrared” mean?

The word “infrared” means light energy just beyond the red end of the visible spectrum, felt as heat but invisible to the eye. In plain terms, invisible heat-radiation light, used in remotes, night vision, and heaters.

How do you pronounce “infrared”?

“Infrared” is pronounced ihnf-ruh-REHD (/ˌɪnfɹəˈɹɛd/ in IPA).

How do you use “infrared” in a sentence?

Here is “infrared” used in a sentence: “Night-vision goggles work by detecting infrared given off by warm bodies.”

What part of speech is “infrared”?

Depending on how it is used, “infrared” can be a noun and an adjective.

Is “infrared” a common word?

“Infrared” is an uncommon word in modern English.

How many meanings does “infrared” have?

“Infrared” has 2 distinct senses listed in this dictionary. The most common is: light energy just beyond the red end of the visible spectrum, felt as heat but invisible to the eye.

What is the difference between infrared and ultraviolet?

Infrared is light energy just beyond the red end of the visible spectrum, felt as heat but invisible to the eye, while ultraviolet lies beyond the opposite, violet end of the spectrum. Infrared is associated with heat, whereas ultraviolet is associated with higher-energy radiation that can cause sunburn.

Why can't humans see infrared light?

Infrared light falls just beyond the red end of the visible spectrum, meaning its wavelengths are outside the range the human eye can detect, though it can still be felt as heat.

What is infrared used for in technology?

Infrared radiation is used in technology relating to or using this kind of energy, such as infrared cameras that detect heat, remote controls, and night-vision devices.

Definitions: FreeDict original editorial