Hidden supply
There are a few possibilities for this:
'hidden supply' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for stash that I've seen before include "Cache" , "(Hidden store of) drugs" , "Secret store of valuables" , "Secret(ly) store" , "Treasure trove" .)
'hidden supply' 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 "Put away" , "Concealed store" , "Secret hiding place" , "Something hidden" , "Hidden store of things" .)
'hidden supply' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for hoard that I've seen before include "(Miser's) store" , "Hard kick" , "Amass and store privately" , "Accumulated store" , "Secret store of valuables" .)