Source : Webster's Revised Unabridged Dictionary (1913)

Oread \O"re*ad\, n. [L. Oreas, -adis, Gr. 'Oreia`s, -a`dos, fr.
   'o`ros mountain: cf. F. or['e]ade.] (Class. Myth.)
   One of the nymphs of mountains and grottoes.

         Like a wood nymph light, Oread or Dryad. --Milton.

Source : WordNet®

Oread
     n : (Greek mythology) one of the mountain nymphs