Definition of Zoroastrianism

Noun: Zoroastrianism  ,zor-ow'as-tree-u,ni-zum or ,zór-ow'as-tree-u,ni-zum [N. Amer], ,zó-row'as-tree-u,ni-zum [Brit]

1. System of religion founded in Persia in the 6th century BC by Zoroaster; set forth in the Zend-Avesta; based on concept of struggle between light (good) and dark (evil)
   - Mazdaism

See also:
Zoroastrian
zoster