One may get belted taking part in this sport (4)
I believe the answer is:
judo
'this sport' is the definition.
(judo is a kind of sport)
'one may get belted taking part' is the wordplay.
I cannot really see how this works, but
'part' could be 'do' (do is a kind of part) and 'do' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
'in' acts as a link.
Can you help me to learn more?
(Other definitions for judo that I've seen before include "Japanese combat sport" , "Throwing sport (from the Japanese for gentleness)" , "Contact sport" , "Martial art (not sumo)" , "13 art of self-defence" .)