taru-adjective, adverb taking the 'to' particle
rugged; craggy; jagged
Formal or literary term used to describe steep, rugged mountains. Often appears in descriptive or poetic contexts.
Rugged mountains stretch in a chain.
A craggy rock face towers above.
Variant spelling without the repetition mark; less common but valid.
The kanji 峨 means 'high mountain' or 'steep', and the repetition 峨々 intensifies the meaning to 'very rugged'. The reading が is the on'yomi. The exact historical derivation is uncertain, but the form is a typical literary reduplication.