Some sponsor a clerical authority (6)
I believe the answer is:
oracle
'authority' is the definition.
(oracle can mean an authority on a topic)
'some sponsor a clerical' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'ORACLE' is hidden within 'sponsor a clerical'.
(Other definitions for oracle that I've seen before include "Source of divine prophesy" , "Agent of divine revelation" , "Source of wisdom, prophet" , "Authority to be consulted" , "Medium for prophecy" .)