The Collaborative International Dictionary of English v.0.48:
Asura \A*su"ra\, n. (Hind. Myth.) An enemy of the gods, esp. one of a race of demons and giants. [1913 Webster]WordNet (r) 3.0 (2006):
Asura n 1: earlier a god; later a demon; counterpart of Zoroastrian Ahura