permafrost

noun

per·​ma·​frost ˈpər-mə-ˌfrȯst How to pronounce permafrost (audio)
: a permanently frozen layer at variable depth below the surface in frigid regions of a planet (such as earth)

Examples of permafrost 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.
While other projections have largely focused on permafrost near the surface, where most of the carbon is stored, the new study accounts for deeper soils. — Jackie Flynn Mogensen, Scientific American, 12 June 2026 Unlike with other major methane sources, such as belching cattle or melting permafrost, the technology to curb emissions from oil and gas operations is already viable, and fairly cheap. — Alex Cuadros, ProPublica, 16 June 2026 To this day, water still exists below the surface of Utopia Planitia in the form of ice and permafrost, with enough to fill Lake Superior on Earth. — Keith Cooper, Space.com, 23 Apr. 2026 As a result, the atmosphere and oceans heat up, increasing the risks of passing tipping points – glaciers disappear, Atlantic Ocean circulation shuts down, permafrost thaws, coral reefs die. — Michael Wysession, Fortune, 6 Mar. 2026 See All Example Sentences for permafrost

Word History

Etymology

permanent + frost

First Known Use

1943, in the meaning defined above

Time Traveler
The first known use of permafrost was in 1943

Rhymes for permafrost

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Browse Nearby Words

permaculture
permafrost
permalloy
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Cite this Entry

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

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Kids Definition

permafrost

noun
per·​ma·​frost ˈpər-mə-ˌfrȯst How to pronounce permafrost (audio)
: a permanently frozen layer at variable depth below the surface in frigid regions of a planet (as earth)

More from Merriam-Webster on permafrost

Britannica.com: Encyclopedia article about permafrost

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