permafrost

[pur-muh-frawst, -frost]

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noun

(in arctic or subarctic regions) perennially frozen subsoil.

Origin of permafrost

First recorded in 1943; perma(nent) + frost

Also called pergelisol.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for permafrost

chunk, glaze, hail, crystal, iceberg, icicle, glacier, sleet, diamonds, hailstone, floe

Examples from the Web for permafrost

Contemporary Examples of permafrost

I wondered what would happen to the trees if some of the permafrost melted, allowing roots to expand in longer growing seasons.
Visiting the Arctic Circle…Before It’s Irreversibly Changed
Terry Greene Sterling
April 1, 2014

British Dictionary definitions for permafrost

permafrost

noun

ground that is permanently frozen, often to great depths, the surface sometimes thawing in the summer

Word Origin for permafrost

C20: from perma (nent) + frost

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for permafrost

1943, coined in English by Russian-born U.S. geologist Siemon W. Muller (1900-1970) from perm(anent) frost.

permafrost in Science

permafrost

[pûr′mə-frôst′]

A layer of soil or bedrock that has been continuously frozen for at least two years and as long as tens of thousands of years. Permafrost can reach depths of up to 1,524 m (4,999 ft). It is found throughout most of the polar regions and underlies about one fifth of the Earth's land surface.