Retailer opening for sales before spring (4)
I believe the answer is:
shop
'retailer' is the definition.
(I know that retailer can be written as shop)
'opening for sales before spring' is the wordplay.
'opening for' suggests taking the first letters.
'before' says to put letters next to each other.
'spring' becomes 'hop' (hopping is a kind of springing).
The first letter of 'sales' is 's'.
's'+'hop'='SHOP'
(Other definitions for shop that I've seen before include "Give away" , "Store or boutique" , "Be disloyal to" , "Where goods are bought and sold" , "Place to buy" .)