1. a layer of soil or rock that remains frozen throughout the year, typically found in polar regions
Usage: geological term

Examples

• The permafrost in Alaska is beginning to thaw due to climate change.
• Scientists study permafrost to understand Arctic ecosystems.
• Buildings in Siberia must be constructed to account for the permafrost beneath.
• Permafrost contains large amounts of trapped carbon.
• The research team drilled deep into the permafrost layer.
• Melting permafrost releases methane into the atmosphere.
• Traditional hunting practices are affected by changes in permafrost.