Eurodollars

Eurodollars are time deposits denominated in U.S. dollars at banks outside the United States, and thus are not under the jurisdiction of the Federal Reserve. Consequently, such deposits are subject to much less regulation than similar deposits within the U.S.. The term was originally coined for U.S. dollars in European banks, but it expanded over the years to its present definition—a U.S. dollar-denominated deposit in Tokyo or Beijing would be likewise deemed a Eurodollar deposit. There is no connection with the euro currency or the eurozone.

More generally, the euro- prefix can be used to indicate any currency held in a country where it is not the official currency: for example, Euroyen or even Euroeuro.

Gradually, after World War II, the quantity of U.S. dollars outside the United States increased enormously, as a result of both the Marshall Plan and imports into the U.S., which had become the largest consumer market after World War II.

As a result, enormous sums of U.S. dollars were in the custody of foreign banks outside the United States. Some foreign countries, including the Soviet Union, also had deposits in U.S. dollars in American banks, granted by certificates. Various history myths exist for the first Eurodollar creation, or booking, but most trace back to Communist governments keeping dollar deposits abroad.

In one version, the first booking traces back to Communist China, which, in 1949, managed to move almost all of its U.S. dollars to the Soviet-owned Banque Commerciale pour l'Europe du Nord in Paris before the United States froze the remaining assets during the Korean War.

...
Wikipedia