Heartless (5)
'heartless' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for callous that I've seen before include "Cruel and unfeeling" , "Heartless" , "Emotionally hardened" , "Hard and unfeeling" , "Hard-hearted" .)
'heartless' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for inhuman that I've seen before include "Cruel, barbaric" , "barbarous and brutal" , "Animal" , "Unfeelingly cruel" , "Cruel, bestial" .)
'heartless' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for cruel that I've seen before include "Devoid of pity" , "Heartless" , "Lucre (anag.)" , "Brutal" , "Painful" .)