Purpose of prison: reforming those inside? (4)
I believe the answer is:
goal
'purpose' is the definition.
(I've seen this in another clue)
'of prison reforming those inside?' is the wordplay.
I cannot really understand how this works, but
'of' could be 'o' and 'o' is found within the answer.
The remaining letters 'gal' 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 goal that I've seen before include "A score in soccer" , "Target (best not one's own!)" , "Something to be achieved" , "could be worth 3 points" , "Target or ambition" .)