For sale in central Hampstead, second-hand (4)
I believe the answer is:
sold
'for sale' is the definition.
Both the definition and answer are adjectives. Maybe you can see an association between them that I don't see?
'central hampstead second-hand' is the wordplay.
'central' says to take the centre.
'second-hand' becomes 'old' (I've seen this in another clue).
The middle letter of 'hampstead' is 's'.
's'+'old'='SOLD'
'in' is the link.
Can you help me to learn more?
(Other definitions for sold that I've seen before include "Persuaded" , "Retailed" , "Betrayed for money" , "Traded" , "Disposed of for money" .)