Reveal there's been a fight outside the ring (5,3)
I believe the answer is:
bring out
'reveal' is the definition.
(synonyms)
'fight outside the ring' is the wordplay.
'fight' becomes 'bout' (as in a bout in boxing).
'outside' is an insertion indicator (some letters go outside others).
'bout' enclosing 'ring' is 'BRING OUT'.
'there's been a' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for bring out that I've seen before include "Publish" , "Issue" , "Emphasise" , "Elicit" , "Emphasize (a feature)" .)