Zoroastrian UK /ˌzɒɹəʊˈæstɹɪən/US /ˌzoʊɹ.oʊˈæs.tɹi.ən/adjective 2noun 1forms 1 adjective2 •relating to or characteristic of Zoroastrianism. •of, by or pertaining to Zoroastrianism. noun1 •a follower of Zoroastrianism formsZoroastrians