Wiktionary
n. An asset such as money or gold that is purchased or accepted as payment for goods and services for its ability to purchase other assets in the future without rapidly losing its purchase power.
Wikipedia
A store of value is the function of an asset that can be saved, retrieved and exchanged at a later time, and be predictably useful when retrieved. The most common store of value in modern times has been money, currency, or a commodity like gold, or financial capital. The point of any store of value is risk management due to a stable demand for the underlying asset.
Usage examples of "store of value".
It is that commodity which serves as a medium of exchange, is universally acceptable to all participants in an exchange economy as payment for their goods or services, and can, therefore, be used as a standard of market value and as a store of value, i.