Run out of fish market (4)
I believe the answer is:
tout
'fish market' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe you can see an association between them that I can't see?
'run out of' is the wordplay.
'run' becomes 'tut' (I can't justify this - if you can you should believe this answer much more).
'out' indicates putting letters inside.
'of' becomes 'o''.
'tut' placed around 'o' is 'TOUT'.
Can you help me to learn more?
(Other definitions for tout that I've seen before include "Sell (tickets) illegally" , "Attempt to sell, perhaps by pestering" , "Try to sell in a direct manner" , "Seek business in a direct manner" , "Attempt to sell (something)" .)