Difficult getting round in store (5)
I believe the answer is:
hoard
'store' is the definition.
(hoarding is a kind of storing)
'difficult getting round in' is the wordplay.
'difficult' becomes 'hard' ('hard' can be a synonym of 'difficult').
'getting round' becomes 'o' (I've seen this in other clues).
'in' is an insertion indicator.
'hard' placed around 'o' is 'HOARD'.
(Other definitions for hoard that I've seen before include "Squirrel away" , "Amass secretly" , "Stockpile" , "Collection" , "One's savings" .)