Reportedly took a chunk out of that woman, showing unrelenting hostility (6)
I believe the answer is:
bitter
'hostility' is the definition.
The definition and answer can be both human attributes as well as being singular nouns.
Maybe you can see an association between them that I can't see?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for bitter that I've seen before include "Kind of British beer" , "Not sweet; very cold" , "Sour British beer?" , "Acrid - beer" , "severe" .)