A Eurodollar is an American dollar that is sitting in a bank outside the United States — first of all in Europe, and later in other places too. Banks use these dollars to lend money and to help companies buy and sell across countries. The name is easy to mix up. Euro here does not mean the euro, the money France and Germany use today. The Eurodollar was already around in the 1950s, long before that money was born. People needed a word for “dollars that live in Europe,” and this is the one that stuck. Though actually, bankers now use it more loosely for dollars held offshore almost anywhere, not only in Europe; the Euro- part became a kind of fossil. You will hear this from bankers and in the business pages, not in the street.

歐洲美元（跟歐元不是同一回事）