Noun
anything that is generally accepted as a standard of value and a measure of wealth in a particular country or region
Source: WordNetThe cumulative development of a medium of exchange on the free market - is the only way money can become established. ... government is powerless to create money for the economy; it can only be developed by the processes of the free market. Murray Rothbard
Money is a commodity ... not a useless token only good for exchanging; ... It differs from other commodities in being demanded mainly as a medium of exchange. Murray Rothbard
Money is the general medium of exchange. It is the thing for which all other goods are traded, the means of final payment for such goods on the market. Murray Rothbard
Time, for Homo economicus, is not "the stream I go a-fishing in.” It is a medium of exchange. We trade our time for money. Curtis White
Austria, Germany and the U.S. South did not disappear as a result of their currencies' ruin. Although many people suffered, most people found a way to survive, life went on, and economic activity eventually resumed after the adoption of a 'reformed' or foreign medium of exchange. Robert Higgs
Money appears as measure (in Homer, e.g. oxen) earlier than as medium of exchange,because in barter each commodity is still its own medium of exchange. But it cannot be its own or its own standard of comparison. Karl Marx