Retailer sounds more disgusting (6)
I believe the answer is:
grocer
'retailer' is the definition.
(I know that grocer is a type of shopkeeper)
'sounds more disgusting' is the wordplay.
'sounds' shows a homophone (sound like).
'more disgusting' becomes 'grosser'.
'grosser' sounds like 'GROCER'.
(Other definitions for grocer that I've seen before include "Merchant who sells foodstuffs" , "Shopkeeper selling food" , "Food shop" , "Market trader" , "Shopkeeper who sells food and household goods" .)