Opposition adjusted to nice job (9)
I believe the answer is:
objection
'opposition' is the definition.
(thesaurus)
'adjusted to nice job' is the wordplay.
'adjusted' indicates anagramming the letters.
'to'+'nice'+'job'='tonicejob'
'tonicejob' with letters rearranged gives 'OBJECTION'.
(Other definitions for objection that I've seen before include "Argument against" , "Statement of protest" , "Demur" .)