Smart boy getting fish (8)
I believe the answer is:
stingray
'fish' is the definition.
(stingray is a kind of fish)
'smart boy' is the wordplay.
'smart' becomes 'sting' (stinging is a kind of smarting).
'boy' becomes 'ray' (**).
'sting'+'ray'='STINGRAY'
'getting' acts as a link.
(Other definitions for stingray that I've seen before include "Large fish with tail spine" , "menace in the water" , "Fish with venomous tail" , "TV show" , "swimmer" .)