meaning of zoroastrianism
1. The religious system of Zoroaster, the legislator and prophet of the ancient Persians, which was the national faith of Persia; mazdeism. The system presupposes a good spirit (Ormuzd) and an opposing evil spirit (Ahriman). Cf. Fire worship, under Fire, and Parsee.
2. 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