A petrodollar is a United States dollar earned by a country through the sale of petroleum. The term was coined by Ibrahim Oweiss, a professor of economics at Georgetown University, in 1973. Oweiss felt there was a need for a word to describe the situation then occurring in oil producing, OPEC countries which were earning large amounts of money, in dollars, from oil production.
The term should not be confused with petrocurrency which refers to the currencies of petroleum exporting nations. However Canada's currency, the Canadian dollar, is sometimes referred to as a petrodollar in this context, as Canada is the largest oil exporter to use the term "dollar" for its currency.