The term 'secret stash' refers to a HOARD or CACHE of items that are kept hidden away from others. It is often used to refer to a collection of items that are valuable or important to the owner, such as money, jewelry, or other items of sentimental value. The terms 'HOARD' and 'CACHE' are often used interchangeably to describe a secret stash, with HOARD being more commonly used in the context of a large collection of items, while CACHE is more often used to refer to a smaller, hidden collection.