The Collaborative International Dictionary of English v.0.48:
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. [Webster 1913 Suppl.]WordNet (r) 3.0 (2006):
arete n 1: a sharp narrow ridge found in rugged mountains