A decrease in the spot value of a currency. A decrease in a currency value relative to another currency in a fixed exchange rate system. The official lowering of the value of one country's currency in terms of one or more foreign currencies. 1. Depreciation.  2. A fall in the value of a currency that has been pegged, either because of an announced reduction in the par value of the currency with the peg continuing, or because the pegged rate is abandoned and the floating rate declines.  3. A fall in the value of a currency in terms of gold or silver, meaningful only under some form of gold standard or silver standard.