Son an amusing character spoils (4)
I believe the answer is:
swag
'spoils' is the definition.
(both can mean the proceeds or prize from something)
'son an amusing character' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'an amusing character' becomes 'wag' (term for a humorous person).
's'+'wag'='SWAG'
(Other definitions for swag that I've seen before include "Burglar's plunder" , "Ill-gotten gains" , "Loop of drapery" , "Burglar's spoils" , "Part of a curtain" .)