The term 'Overseas Dollar' refers to a currency that is used outside of the country of origin. The most common example of this is the Euro, which is used in many countries across Europe. The Euro is the official currency of the European Union and is used by 19 of its member states. It is also used by several other countries outside of the EU, such as Monaco, San Marino, and Vatican City. The Euro is the second-most traded currency in the world after the US Dollar.