Boxing champion employed in the circus (10)
I believe the answer is:
ringmaster
'boxing champion' is the definition.
The answer and definition can be both people as well as being singular nouns.
Maybe you can see a link between them that I don't see?
'employed in the circus' is the wordplay.
I cannot really understand how this works, but
'in' is within the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for ringmaster that I've seen before include "Circus employee" , "Circus controller" , "showman" , "Circus MC" , "Circus compere" .)