Insensitive person (5)
I believe the answer is:
brute
'insensitive person' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for brute that I've seen before include "'Et tu, - - !' (J.Caesar)" , "Savage person" , "Caliban" , "Cruel creature" , "Heartless individual" .)