Sob, uneasier about city (6,5)
I believe the answer is:
buenos aires
'city' is the definition.
(Buenos Aires is an example)
'sob uneasier about' is the wordplay.
'about' indicates an anagram.
'sob'+'uneasier'='sobuneasier'
'sobuneasier' anagrammed gives 'BUENOS AIRES'.
(Other definitions for buenos aires that I've seen before include "Capital of Argentina" , "South American captial" , "Sabine roues (anag) -- Spanish-speaking city" , "Capital city -- uneasier sob (anag)" , "South American capital" .)