Very well, do better friend! (9)
I believe the answer is:
capitally
'very well' is the definition.
(I've seen this before)
'do better friend' is the wordplay.
I cannot really understand how this works, but
'better' could be 'cap' (both can mean to beat somebody else's attempt) and 'cap' is found in the answer.
'friend' could be 'ally' (an ally is a friend or supporter) and 'ally' is present in the answer.
The remaining letters 'it' 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 capitally that I've seen before include "Admirably" , "Very well" , "in a fine manner" .)