Toy has right to be amusing (5)
I believe the answer is:
droll
'be amusing' is the definition.
(I've seen this in another clue)
'toy has right' is the wordplay.
'toy' becomes 'doll' (doll is a kind of toy).
'has' is an insertion indicator.
'right' becomes 'r' (common abbreviation).
'doll' going around 'r' is 'DROLL'.
'to' acts as a link.
(Other definitions for droll that I've seen before include "Dry" , "Drily witty" , "Amusing in offbeat way" , "Mildly amusing" , "Comical in an odd or whimsical manner" .)