The name of the European single The money used in a particular country at a particular time, like dollar, yen, euro, etc., consisting of banknotes and coins, that does not require endorsement as a medium of exchange. adopted by the European Council at the meeting held in Madrid on 15-16 December 1995. See A unit of account used by European Economic Community composed of a basket of member country currencies. The value of the ECU was calculated as a weighted average of the value of the currencies that comprised the basket. On 1 January 1999, the euro replaced the ECU at parity..