Tell cleric not to start (6)
I believe the answer is:
relate
'tell' is the definition.
(as in to tell or relate a story)
'cleric not to start' is the wordplay.
'cleric' becomes 'prelate' (I've seen this before).
'not to start' means to remove the first letter.
'prelate' with its initial letter removed is 'RELATE'.
(Other definitions for relate that I've seen before include "Marriage Guidance - report" , "Recount" , "Narrate, tell in detail" , "Narrate in Tralee" , "Tell - the marriage guidance people" .)