Brief result of amateur boxing scam (7)
I believe the answer is:
laconic
'brief' is the definition.
(synonyms)
'amateur boxing scam' is the wordplay.
'amateur' becomes 'laic' (I can't explain this - if you can you should give a lot more credence to this answer).
'boxing' is an insertion indicator ('box' can mean contain, as in to put in a box).
'scam' becomes 'con' (both can mean a fraudulent scheme).
'laic' going around 'con' is 'LACONIC'.
'result of' is the link.
Can you help me to learn more?
(Other definitions for laconic that I've seen before include "with little expression" , "Conical (anag) - pithy" , "Saying little" , "'Curt, terse (7)'" , "Spartan" .)