Bung very quietly into store, perhaps (7)
I believe the answer is:
stopper
'bung' is the definition.
(I've seen this before)
'quietly into store perhaps' is the wordplay.
'quietly' becomes 'pp' (musical abbreviation for pianissimo).
'into' means one lot of letters goes inside another.
'perhaps' is an anagram indicator.
'store' anagrammed gives 'stoer'.
'pp' inserted inside 'stoer' is 'STOPPER'.
'very' is the link.
(Other definitions for stopper that I've seen before include "Plug for a bottle" , "One blocks" , "Plug - cork" , "Bung" , "Perhaps cork" .)