Oreades

Oreades in the Greek mythology nymphs of the mountains, with special names appropriate to the district they severally inhabit.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)

Orders in Council * Oregon
Orange River Colony
Orangemen
Oratorio
Oratory, Congregation of the
Orcagna
Orchardson, William Quiller
Orcus
Ordeal
Ordericus Vitalis
Orders in Council
Oreades
Oregon
Orelli, Conrad von
Orelli, Johann Kaspar von
Orestes
Orfila, M. J. Bonaventure
Organism
Organon
Orgies
Oriflamme
Origen