Definition of firn in English:



  • [mass noun] Crystalline or granular snow, especially on the upper part of a glacier, where it has not yet been compressed into ice.

    • ‘About a quarter of that shrinkage, or 7 cm, may have resulted from snow packing down into denser material called firn, says Andrew Shepherd, a glaciologist at the University of Cambridge in England.’
    • ‘Combine such dense firn with a daily rhythm of freeze and thaw, and spring avalanche danger is easy to predict and avoid.’


Mid 19th century: from German, from Old High German firni old; related to Swedish forn former.