Debasement

A debasement of coinage is the practice of lowering the intrinsic value of coins, especially when used in connection with commodity money, such as gold or silver coins, while continuing to circulate it at face value. A coin is said to be debased if the quantity of gold, silver, copper or nickel in the coin is reduced.

Debasement is a practice of governments, and in government debasement, governments make their debased coins legal tender, which is not something private minters can do given that the practice cannot be easily engaged in without a government requiring that people accept debased coins.