Buried Roman city (7)
I believe the answer is:
pompeii
'buried roman city' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for pompeii that I've seen before include "Site of an Italian disaster of AD79" , "City buried by volcanic eruption, AD 79" , "Roman site" , "Ancient city near Naples destroyed by volcano" , "Roman town buried by Vesuvius" .)