Main city (7)
'main city' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for metropolis that I've seen before include "Urban centre" , "See" , "early film" , "Very large city" , "London, say" .)
'main city' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for capital that I've seen before include "Big money?" , "city such as London" , "Excellent - assets - first city" , "Upper-case letter" , "Madrid, say" .)