Nobody put rats out (7)
I believe the answer is:
upstart
'nobody' is the definition.
(thesaurus)
'put rats out' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'put'+'rats'='putrats'
'putrats' anagrammed gives 'UPSTART'.
(Other definitions for upstart that I've seen before include "Person risen to high position, arrogant with it" , "Person recently elevated and arrogant with it" , "Arriviste, parvenu" , "Recent promotees, say, behaving with arrogance" , "mushroom" .)