Back to be dealt with by churl (3)
I believe the answer is:
oaf
'churl' is the definition.
'back to be dealt with' is the wordplay.
'back' says the letters should be written in reverse.
'to be dealt with' becomes 'fao' (abbreviation for 'for attention of').
'fao' written backwards gives 'OAF'.
'by' is the link.
(Other definitions for oaf that I've seen before include "Stupid or boorish man" , "A clumsy or stupid person" , "Clod" , "Stupid lout" , "Lout, lummox" .)