Smart effort surrounds a city (7)
I believe the answer is:
chicago
'city' is the definition.
(I know that Chicago is a city)
'smart effort surrounds a' is the wordplay.
'smart' becomes 'chic' (both can mean stylish).
'effort' becomes 'go' (go is a kind of effort).
'surrounds' means one lot of letters goes inside another.
'chic'+'go'='chicgo'
'chicgo' going around 'a' is 'CHICAGO'.
(Other definitions for chicago that I've seen before include "City on Lake Michigan" , "America's Windy City" , "Illinois port" , "American city; musical" , "Al Capone's city" .)