Source : Webster's Revised Unabridged Dictionary (1913)

Arete \A`r[^e]te"\, n. [F., lit., a sharp fish bone, ridge,
   sharp edge, fr. L. arista beard of grain.] (Geog.)
   An acute and rugged crest of a mountain range or a subsidiary
   ridge between two mountain gorges.

Source : WordNet®

arete
     n : a sharp narrow ridge found in rugged mountains