You won't find this concealed in violent hatred! (4)
I believe the answer is:
that
'you won't find' is the definition.
I can't tell whether this defines the answer.
'concealed in violent hatred' is the wordplay.
'concealed in' indicates the answer is hidden within the clue.
'THAT' can be found hidden inside 'violent hatred'.
'this' acts as a link.
Can you help me to learn more?
(Other definitions for that that I've seen before include "Not 8 Ac but the other" , "The (one) there" , "Just like --; -- is to say" , "Yon" , "See 5" .)