/zawr'oh as"tree euh niz'euhm, zohr'-/ , n.
an Iranian religion, founded c600 B.C. by Zoroaster, the principal beliefs of which are in the existence of a supreme deity, Ahura Mazda, and in a cosmic struggle between a spirit of good, Spenta Mainyu, and a spirit of evil, Angra Mainyu.
Also, Zoroastrism . Also called Mazdaism .
[ 1850-55; ZOROASTRIAN + -ISM ]