Earlier head of religious order (5)
I believe the answer is:
prior
This clue is a double definition.
'earlier' is the first definition.
(synonyms)
'head of religious order' is the second definition.
(head of a priory)
(Other definitions for prior that I've seen before include "head of a house of friars" , "figure of authority in retreat" , "Deputy head of an abbey" , "Erstwhile" , "Foregoing - cleric" .)