Intending to do harm (9)
I believe the answer is:
malicious
'intending to do harm' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for malicious that I've seen before include "Intending to do harm" , "Deliberately harmful" , "Malevolent, spiteful" , "bad" , "Bearing ill-will" .)