Plural of arete; sharp, narrow ridges on mountains formed by erosion, typically between glaciated valleys; also, virtues or excellences in ancient Greek philosophy.
From Greek 'arete' (sharp edge, virtue). The geographical sense (mountain ridges) comes from French alpinists' usage in the 19th century, while the philosophical sense is ancient.
The word 'arete' has two completely different meanings—climbers scrambling up a knife-edge ridge are literally climbing a 'virtue' according to the word's etymology!
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