Gloomy place to sell illegally (5,6)
I believe the answer is:
black market
'sell illegally' is the definition.
The answer and definition can be both to do with ownership as well as being verbs in their base form.
Maybe there's a link between them I don't understand?
'gloomy place' is the wordplay.
'gloomy' becomes 'black' (I've seen this before).
'place' becomes 'market' (I am not sure about this - if you are sure you should believe this answer much more).
'black'+'market'='BLACK-MARKET'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for black market that I've seen before include "Covert trade in illicit goods" , "Buying and selling in violation of rationing" , "Illegal system of trade" , "Place to purchase illicit goods" , "Illicit trading" .)