Excessively recoiling part of blowtorch-cum-revolver (8)
I believe the answer is:
overmuch
'excessively' is the definition.
(thesaurus)
'recoiling part of blowtorch-cum-revolver' is the wordplay.
'recoiling' is a reversal indicator.
'part of' indicates a hidden word.
'hcumrevo' is hidden in the letters of 'blowtorch cum revolver'.
'hcumrevo' backwards is 'OVERMUCH'.
(Other definitions for overmuch that I've seen before include "Too large an amount" , "To too great an extent" , "Excessively" , "Excessive amount" .)