Animal not heartless, having earlier been awfully kind (10)
I believe the answer is:
benevolent
'kind' is the definition.
(similar in meaning)
'animal not heartless having earlier been awfully' is the wordplay.
I cannot quite understand how this works, but
'not' could be 'nt' (synonyms) and 'nt' is present in the answer.
an anagram of 'been' is 'bene' which is located in the answer.
The remaining letters 'vole' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for benevolent that I've seen before include "Charitable" , "Philanthropic" , "Well disposed" , "Well meaning, kindly" , "Kind" .)