Fierce; cruel (9)
I believe the answer is:
truculent
This clue is a double definition.
'fierce' is the first definition.
(thesaurus)
'cruel' is the second definition.
(thesaurus)
(Other definitions for truculent that I've seen before include "Aggressively defiant" , "Surly" , "Obstreperous" , "Defiantly aggressive" , "Rude and aggressive" .)