Criminal executed after pardon (7)
I believe the answer is:
condone
'pardon' is the definition.
(thesaurus)
'criminal executed after' is the wordplay.
'criminal' becomes 'con' (abbreviation for 'convict').
'executed' becomes 'done' (I've seen this in other clues).
'after' means one lot of letters go next to another.
'con'+'done'='CONDONE'
(Other definitions for condone that I've seen before include "'Excuse, overlook (7)'" , "Reluctantly sanction" , "Overlook - forgive" , "Accept or forgive (bad behaviour)" , "Forgive, sanction" .)