to lower the value of money, for instance by making metal coins from a less valuable substance, borrowing too much against the current value of that money, etc.

The only way out of this is to debase the currency.

In the last years of his reign, he spent huge sums on war and debased the coinage of the empire.

Desperate governments down the ages have always debased the currency.

The currency had been debased, leading to violent inflation.

Charles had threatened to debase the coinage by reminting it.