irradiance

noun

ir·​ra·​di·​ance i-ˈrā-dē-ən(t)s How to pronounce irradiance (audio)
1
: radiance sense 1
2
: the density of radiation incident on a given surface usually expressed in watts per square centimeter or square meter

Examples of irradiance in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Skip TikTok Shop dupes that don’t publish wavelength or irradiance numbers. — Allison Palmer updated June 24, Kansas City Star, 24 June 2026 Solar power works for missions close to the sun, but by the time a spacecraft gets to Jupiter, the available solar irradiance drops below 4 percent of that on Earth. — IEEE Spectrum, 25 Aug. 2025 Red light device manufacturer Bon Charge co-founder, Katie Mant, notes that the most relevant factor is irradiance, which is the dose of light delivered per square centimeter. — Emily Peck, Wired News, 12 Dec. 2025 Researchers isolated phenomena including the El Niño weather phase, volcanic eruptions and solar irradiance. — Los Angeles Times, 9 Mar. 2026 See All Example Sentences for irradiance

Word History

First Known Use

1599, in the meaning defined at sense 1

Time Traveler
The first known use of irradiance was in 1599

Rhymes for irradiance

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Browse Nearby Words

irr
irradiance
irradiancy
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Cite this Entry

“Irradiance.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/irradiance. Accessed 7 Jul. 2026.

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Medical Definition

irradiance

noun
ir·​ra·​di·​ance ir-ˈād-ē-ən(t)s How to pronounce irradiance (audio)
: the density of radiation incident on a given surface usually expressed in watts per square centimeter or square meter
Last Updated: - Updated example sentences
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