Archdeacon and defaulter reported feud (8)
I believe the answer is:
vendetta
'feud' is the definition.
(vendetta is a kind of feud)
'archdeacon and defaulter reported' is the wordplay.
I cannot quite understand how this works, but
'archdeacon' could be 'ven' and 'ven' is found within the answer.
This explanation may well be incorrect...
(Other definitions for vendetta that I've seen before include "A family feud in Sicily" , "Private feud" , "Unremitting battle" , "ongoing row" , "Long bitter row" .)