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

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

Arctic climate change – manifesting in sea ice loss, permafrost thaw and coastal erosion, among other phenomena – is already causing serious problems for Arctic residents, ecosystems and the rest of the planet. — David Balton, The Conversation, 15 June 2026

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

Early-warning system As climate change accelerates the retreat of tidewater glaciers and thaws the permafrost holding Arctic mountains together, the structural integrity of these landscapes is failing. — Jacek Krywko, ArsTechnica, 10 May 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)