Zoroastrian (adj.) Look up Zoroastrian at Dictionary.com
1743, from Zoroaster, from Latin Zoroastres, from Old Persian Zarathushtra, 6c. or 7c. B.C.E. Persian religious teacher. The name appears to be literally "whose camels are old," from *zarant "old" (cognate with Greek geron, genitive gerontos "old;" see gerontology) + ushtra "camel." As a noun from 1811.