Discover the point has penetrated the heart of the brute (5)
I believe the answer is:
fiend
'the brute' is the definition.
(I've seen this in another clue)
'discover the point has penetrated the heart' is the wordplay.
'discover the point' becomes 'find' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'has' means one lot of letters goes inside another.
'penetrated' becomes 'entered' (I've seen this in another clue).
'the heart' says to take the centre.
The middle letter of 'entered' is 'e'.
'find' going around 'e' is 'FIEND'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for fiend that I've seen before include "Demon, ogre" , "Evil supernatural being" , "addict" , "Demon; cruel person" , "Wicked and inhuman person" .)