Chest collected by metropolitan outlet (6)
I believe the answer is:
market
'outlet' is the definition.
(I know that market is a type of outlet)
'chest collected by metropolitan' is the wordplay.
I cannot quite understand how this works, but
'chest' could be 'ark' (historical term for a chest) and 'ark' is found in the answer.
'collected' could be 'met' (I've seen this in another clue) and 'met' is located in the leftover letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for market that I've seen before include "bargain" , "Bazaar" , "Place of commercial activity" , "Trading place" , "Commercial area" .)