Store licensed to supply this souvenir (5)
I believe the answer is:
relic
'this souvenir' is the definition.
(synonyms)
'store licensed to supply' is the wordplay.
'to supply' indicates a hidden word (I've seen 'supplying' mean this).
'RELIC' can be found hidden inside 'store licensed'.
(Other definitions for relic that I've seen before include "Personal saintly memorial" , "Ancient survival" , "Part of a holy person's body or possession" , "for remembrance" , "One may venerate this" .)