Try to cage rook that hurt amusing brother (7)
I believe the answer is:
groucho
'amusing brother' is the definition.
(one of the Marx Brothers)
'try to cage rook that hurt' is the wordplay.
'try' becomes 'go' (both can mean an attempt).
'to cage' is an insertion indicator (inserted letters are locked up).
'rook' becomes 'R' (chess abbreviation).
'that hurt' becomes 'ouch' (expression of pain).
'r'+'ouch'='rouch'
'go' placed around 'rouch' is 'GROUCHO'.
(Other definitions for groucho that I've seen before include "The Marx Brother with the moustache" , "One of Marx Brothers" , "Funny man" , "A Marx; a club" , "One of Harpo's brothers" .)