Devaluation

Devaluation is most often used in situation where a currency has a defined value relative to the baseline. Historically, early currencies were typically coins struck from gold or silver by an issuing authority which certified the weight and purity of the precious metal. A government in need of money and short on precious metal might abruptly lower the weight or purity of the coins without announcing this, or else decree that the new coins had equal value to the old, thus devaluing the currency.