Store providing new hats at central Ruislip (5)
I believe the answer is:
stash
'store' is the definition.
(stash is a kind of store)
'new hats at central ruislip' is the wordplay.
'new' is an anagram indicator.
'at' says to put letters next to each other (I've seen this in other clues).
'central' means to look at the middle letters.
The centre of 'ruislip' is 's'.
'hats' is an anagram of 'tash'.
'tash' after 's' is 'STASH'.
'providing' is the link.
(Other definitions for stash that I've seen before include "Treasure trove" , "Consignment of drugs" , "collection" , "Hide in a secret place" , "Stow away" .)