Hiding place for treasure (5)
I believe the answer is:
cache
'hiding place for treasure' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for cache that I've seen before include "Hiding-place for treasure etc" , "(Place in) hidden store" , "Collection of hidden things" , "Hiding place for treasure or store" , "what things could be stored in" .)