Country diet aunt sets out (6,6)
I believe the answer is:
united states
'country' is the definition.
(United States is an example)
'diet aunt sets out' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'diet'+'aunt'+'sets'='dietauntsets'
'dietauntsets' anagrammed gives 'UNITED STATES'.
(Other definitions for united states that I've seen before include "Country, capital Washington DC" , "National federation" .)