Wildebeest sent back after good man's bitten (5)
I believe the answer is:
stung
'bitten' is the definition.
('sting' can be a synonym of 'bite')
'wildebeest sent back after good man's' is the wordplay.
'wildebeest' becomes 'gnu' ('gnu' can be a synonym of 'wildebeest').
'sent back' shows that the letters should be reversed in order.
'after' is a charade indicator (letters next to each other).
'good man' becomes 'st'.
'gnu' backwards is 'ung'.
'ung' put after 'st' is 'STUNG'.
(Other definitions for stung that I've seen before include "Bitten, by a bee say" , "Punctured eg by wasp" , "Bitten, pierced" , "Wounded by, eg, bee" , "Aroused to impatience or anger" .)