Wrong sort of paint (5)
I believe the answer is:
inapt
'wrong' is the definition.
(thesaurus)
'sort of paint' is the wordplay.
'sort of' indicates an anagram.
'paint' with letters rearranged gives 'INAPT'.
(Other definitions for inapt that I've seen before include "Free from deceit" , "Useless" , "Cartoon duck" , "not seemly" , "Unsuited" .)