Causes a commotion about boxing lawsuit (4)
I believe the answer is:
case
'lawsuit' is the definition.
('case' can be a synonym of 'lawsuit')
'causes a commotion about boxing' is the wordplay.
'boxing' says the answer is hidden in the clue (the solution is contained or boxed up by the clue).
'about' says the letters should be written backwards.
'esac' is hidden within 'causes a commotion'.
'esac' in reverse letter order is 'CASE'.
(Other definitions for case that I've seen before include "that paperback lacks?" , "condition" , "proceedings" , "Box of twelve bottles of wine" , "suit for trial" .)