Shoe salesman returned after blunder (7)
I believe the answer is:
slipper
'shoe' is the definition.
(I've seen this before)
'salesman returned after blunder' is the wordplay.
'salesman' becomes 'rep' (sales rep).
'returned' shows that the letters should be reversed in order.
'after' means one lot of letters go next to another.
'blunder' becomes 'slip' (slip is a kind of blunder).
'rep' in reverse letter order is 'per'.
'per' put after 'slip' is 'SLIPPER'.
(Other definitions for slipper that I've seen before include "Shoe worn indoors" , "Beat; mule" , "Nearby; pub" , "One losing footing" , "Light shoe" .)