Scoundrel mad about city (9)
I believe the answer is:
rotterdam
'city' is the definition.
(Rotterdam is an example)
'scoundrel mad about' is the wordplay.
'scoundrel' becomes 'rotter' (both can mean a nasty person).
'about' says the letters should be written in reverse.
'mad' reversed gives 'dam'.
'rotter'+'dam'='ROTTERDAM'
(Other definitions for rotterdam that I've seen before include "One of the world's largest ports" , "Dutch city and port" , "city abroad" , "foreign city" , "European city" .)