The Collaborative International Dictionary of English v.0.48:

Bergschrund \Berg"schrund`\, n. [G., lit., mountain gap.] (Phys.
   Geog.)
   The crevasse or series of crevasses, usually deep and often
   broad, frequently occurring near the head of a mountain
   glacier, about where the n['e]v['e] field joins the valley
   portion of the glacier.
   [Webster 1913 Suppl.]