The most common and most likely answer to this crossword clue is the 10 letter word METROPOLIS
I've seen this crossword clue in Independent
M
E
T
R
O
P
O
L
I
S
More clues leading to the result METROPOLIS
- Mice emptied place for grain left over in London, say
- Mice emptied place for grain left over in city
- Permit Oslo or Rome to slip badly as city
- City of Rome spoilt, sadly
- Bumped into core of strong Irish police in capital
- Development of prime lots around old capital
- City, capital city, one becoming nothing in endless chaos
- Chief city in Middle East – large container port set up
- Farm store left ’em upset in the city
- Chief city in Middle East? Large container port set up
Buddy explains!

The straight part
We know that "city" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case city = metropolis.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does METROPOLIS mean?
METROPOLIS noun- (history) The mother (founding) polis (city state) of a colony.
- A large, busy city, especially as the main city in an area or country or as distinguished from surrounding rural areas.
- (canon law) The see of a metropolitan archbishop, ranking above its suffragan diocesan bishops.
- A generic focus in the distribution of plants or animals.