Starting sale of a Chesterfield (4)
I believe the answer is:
sofa
'chesterfield' is the definition.
(I've seen this in another clue)
'starting sale of a' is the wordplay.
'starting' suggests taking the first letters.
The initial letter of 'sale' is 's'.
's'+'of'+'a'='SOFA'
(Other definitions for sofa that I've seen before include "Upholstered seat for two or more" , "Long upholstered seat with back and arms" , "Item of furniture" , "Couch" , "Somewhere to sit" .)