Definition of permafrost
: a permanently frozen layer at variable depth below the surface in frigid regions of a planet (such as earth)
Recent Examples of permafrost from the Web
Cool, dry permafrost can preserve prehistoric DNA like a natural freezer, but Egypt is a gene incinerator.
To be fair, many Russian oil fields are in the far north, where wells are burrowed under permafrost and will freeze if production halts; the industry cannot easily cut output without permanently damaging its wells.
But the supports for the pipeline are anchored in permafrost, which is now melting.
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Origin and Etymology of permafrost
permanent + frost
First Known Use: 1943
PERMAFROST Defined for English Language Learners
Definition of permafrost for English Language Learners
: a layer of soil that is always frozen in very cold regions of the world
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