Ahura' (Zend.). The same as Asura, the holy, the Breath-like. Ahura Mazda, the Ormuzd of the Zoroastrians or Parsis, is the Lord who bestows light and intelligence, whose symbol is the Sun (See “Ahura Mazda”), and of whom Ahriman, a European form of “Angra Mainyu” (q.v.), is the dark aspect.
Source: H.P.Blavatsky - The Theosophical Glossary