Injures with hot weapons (5)
I believe the answer is:
'injures' is the definition.
(harming is a kind of injuring)
'with hot weapons' is the wordplay.
'with' says to put letters next to each other.
'hot' becomes 'h' (abbreviation eg on taps).
'weapons' becomes 'arms' ('arm' can be a synonym of 'weapon').
'h' next to 'arms' is 'HARMS'.
(Other definitions for harms that I've seen before include "Hurts, damages" , "Wounds" , "Injures, damages" .)