Zoroastrian administrator with repetitive strain injury (5)
I believe the answer is:
parsi
'zoroastrian' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for parsi that I've seen before include "Zoroastrianism adherent" , "Zoroastrian descendant; Persian dialect" , "Ancient Persian dialect" , "Member of a monotheistic Asian sect" , "non-Christian monotheist" .)