Lewis Short
(adjective) : Zōrŏastres, is, m.
* Zoroaster, a lawgiver of the Medes, Just. 1, 1, 9; Plin. 30, 1, 2, § 3; App. Mag. p. 291.—Hence, Zōrŏ-astrēus, a, um, , of or belonging to Zoroaster, Zoroastrian: susurri,i. e. magical,Prud. Apoth. 494 (where Zŏr-, by solecism).
Charlton T. Lewis, Charles Short, A Latin Dictionary