A monetary system in which two precious metals, usually gold and silver, were used as the basis for currency. The idea of having two metals as a currency standard derived from the idea that two commodities rather than one alone would make a more stable basis for currency values.

A government's commission to exchange its currency on demand for stated amounts of either of two metals, usually gold or silver. Also bimetallic standard. Compared with symmetallism. See also Symmetallism.

In economics, bimetallism is a monetary standard in which the value of the monetary unit can be expressed either with a certain amount of gold or with a certain amount of silver. The ratio between the two metals is fixed by law.