Zoroastrian (5)
I believe the answer is:
parsi
'zoroastrian' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for parsi that I've seen before include "Zoroastrian descendant; Persian dialect" , "Religious believer" , "Indian" , "Ancient Persian dialect" , "Zoroastrianism adherent" .)