EUROPEAN CURRENCY UNIT: The forerunner of the euro that will be officially introduced in the European Union in 2002. Commonly referred to as the ECU, the European Currency Unit is the weighted average of the currencies of the twelve original nations of the European Union. In that there are is no paper currency yet, it is currently used primarily for big-time commercial, financial, and international transactions. See also | European Union | Maastricht Treaty | euro | monetary policy | Economic and Monetary Union | Euro zone | European System of Central Banks |