Mithraism

Origin

Translation (1903) of French mithriacisme, as used in 1899 by Franz Cumont as shorthand for "mystères de Mithra". Cumont was convinced that Mithraism was "Roman Mazdaism", hence his (and earlier) treatments of Latin Mithras and Avestan Mithra as synonyms, and the continuing de-inflection of the Latin name (vocative) as French Mithra.

Full definition of Mithraism

Proper noun

1. An astrology-centric, middle-platonic mystery cult of the 1st-4th century Roman Empire that claimed to have been founded by "Zoroaster".