City of Rome spoilt in ruins (10)
I believe the answer is:
metropolis
'city' is the definition.
('metropolis' can be a synonym of 'city')
'rome spoilt in ruins' is the wordplay.
'in ruins' is an anagram indicator.
'rome'+'spoilt'='romespoilt'
'romespoilt' anagrammed gives 'METROPOLIS'.
'of' acts as a link.
(Other definitions for metropolis that I've seen before include "Main city" , "capital" , "Urban centre" , "Big city" , "chief centre" .)