secret stash

Translations
тайный тайник
Someone found a secret stash of old coins in the attic.
Кто-то нашёл тайный тайник со старыми монетами на чердаке.
Definitions
A secret stash refers to a hidden collection of items, often valuable or illicit, that is kept out of sight to avoid detection or to preserve its secrecy.
Words
secret

adjective
тайный
stash

noun
тайник