Shopkeeper could be fresh and more vulgar, when heard (11)
I believe the answer is:
greengrocer
'shopkeeper' is the definition.
(I've seen this before)
'fresh and more vulgar when heard' is the wordplay.
'fresh' becomes 'green' (I've seen this before).
'and' means one lot of letters go next to another.
'more vulgar' becomes 'grosser' (I've seen this before).
'when heard' shows a homophone (sound like).
'grosser' is a homophone of 'grocer'.
'green'+'grocer'='GREENGROCER'
'could be' acts as a link.
(Other definitions for greengrocer that I've seen before include "Dealer in fruit and vegetables" , "Fruit and veg merchant" , "Muslim month of fasting" , "Fruit and veg seller" , "Retailer of fruit and vegetables" .)