The setter's right and wrong (8)
I believe the answer is:
improper
'wrong' is the definition.
(I know that wrong can be written as improper)
'the setter's right' is the wordplay.
'the setter's' becomes 'Im' (I've seen this in other clues).
'right' becomes 'proper' (similar in meaning).
'im'+'proper'='IMPROPER'
'and' is the link.
(Other definitions for improper that I've seen before include "Naughty" , "Not conforming to norms of conduct, maybe indecent" , "Not fitting" , "Inappropriate" , "Unseemly; (fraction) more than one" .)