An excellent punishment? (4)
I believe the answer is:
fine
I believe this clue is a double definition.
'an excellent' is the first definition.
(I've seen this before)
'punishment?' is the second definition.
(fine is a kind of punishment)
(Other definitions for fine that I've seen before include "It's all right" , "Sheer or very good" , "Magnificent" , "Money paid as penalty" , "Fair - penalty" .)