permafrost

noun

per·​ma·​frost ˈpər-mə-ˌfrȯst 

: 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

Shorelines in this part of Alaska are now more vulnerable to erosion due, in part, to decreasing sea ice and permafrost thaw. — Samantha Watson, NPR, 19 Sep. 2026

Increasing greenhouse gas concentrations, largely from burning fossil fuels, have pushed global temperatures so high that sea levels are rising, and shrinking glaciers and thawing permafrost are leaving mountainsides less stable. — Tarun Gopalakrishnan, The Conversation, 18 Sep. 2026

Shugar notes that changes in the weather could have contributed to the conditions that caused this flood, not just the melting of permafrost. — Thor Benson, Rolling Stone, 2 Sep. 2026

An incident of the massive scale seen in Nepal is rare, but smaller, similar disasters will be more frequent in the future as the melting of glaciers and permafrost creates unstable bedrock in mountains, according to Cook. — Megan Fahrney, ABC News, 1 Sep. 2026

Word History

Etymology

permanent + frost

First Known Use

1943, in the meaning defined above

Rhymes for permafrost

• holocaust
• accost
• crisscrossed
• defrost
• embossed
• exhaust
• recrossed
• uncrossed
• bossed
• cost
• crossed
• dost

Kids Definition

permafrost

noun

per·​ma·​frost ˈpər-mə-ˌfrȯst 

: a permanently frozen layer at variable depth below the surface in frigid regions of a planet (as earth)