Absolutely miserable fitting (9)
I believe the answer is:
downright
'absolutely' is the definition.
(thesaurus)
'miserable fitting' is the wordplay.
'miserable' becomes 'down'.
'fitting' becomes 'right' (I've seen this before).
'down'+'right'='DOWNRIGHT'
(Other definitions for downright that I've seen before include "Absolutely!" , "Utter, complete" , "Utter, arrant" , "True" , "Out-and-out" .)