Unhappy with half the fine still to be paid out (6)
I believe the answer is:
pained
'still to be paid out' is the definition.
I can't tell whether this definition defines the answer.
'unhappy with half the fine' is the wordplay.
'unhappy' becomes 'paid' (I can't explain this - if you can you should believe this answer much more).
'with' indicates putting letters inside.
'half' means to take half the letters.
'fine' with half the letters taken is 'ne'.
'paid' placed around 'ne' is 'PAINED'.
Can you help me to learn more?
(Other definitions for pained that I've seen before include "Distressed so it hurts?" , "Distressed or hurt in feelings" , "Hurt and disapproving (6)" , "Distressed and annoyed - hurted" , "Caused suffering to" .)