Stirring paint is not appropriate (5)
I believe the answer is:
inapt
'not appropriate' is the definition.
(inapt means inappropriate or ill-fitting)
'stirring paint' is the wordplay.
'stirring' is an anagram indicator.
'paint' with letters rearranged gives 'INAPT'.
'is' is the link.
(Other definitions for inapt that I've seen before include "unqualified" , "Not suitable or appropriate" , "Inappropriate" , "Cartoon duck" , "Far from fit" .)