One's own little drug-store (5)

I believe the answer is:

stash

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'store' is the definition.
(I know that stash is a type of store)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for stash that I've seen before include "Secret store of valuables" , "Hide (something) away" , "Squirrel away" , "Secret store (colloq.)" , "collection" .)

I've seen this clue in the Evening Standard.

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