Dictionary.com

permafrost

[ pur-muh-frawst, -frost ]
/ ˈpɜr məˌfrɔst, -ˌfrɒst /
Save This Word!

noun

(in Arctic or subarctic regions) perennially frozen subsoil.

QUIZZES

THINK YOU’VE GOT A HANDLE ON THIS US STATE NICKNAME QUIZ?

Did you ever collect all those state quarters? Put them to good use on this quiz about curious state monikers and the facts around them.
Question 1 of 8
Mississippi’s nickname comes from the magnificent trees that grow there. What is it?
Also called pergelisol.

Origin of permafrost

First recorded in 1943; perma(nent) + frost
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

Example sentences from the Web for permafrost

British Dictionary definitions for permafrost

permafrost
/ (ˈpɜːməˌfrɒst) /

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

Scientific definitions for permafrost

permafrost
[ pûrmə-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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Book Your Online Tutor Now