The piastre or piaster was a unit of currency. It was originally equal to one silver dollar or peso, served as the major unit of currency of French Indochina (Present-day Vietnam, Cambodia, and Laos), and in the Ottoman Empire.
As a main unit
As a subunit
- Early private bank currency issues in French-speaking regions of Canada were denominated in piastres. The term is still unofficially used in Quebec and Acadian slang as a reference to the Canadian dollar (the official French term for the modern Canadian dollar is dollar).
- Piastre was also the original French word for the United States dollar, used for example in the French text of the Louisiana Purchase and that usage is still common in Cajun French. Modern French uses dollar for this unit of currency as well. The term is still used as slang for US dollars in the French speaking Caribbean islands, most notably Haiti.
- Piastre is another name for kuruş, 1/100 of the Turkish new lira, as well as the old lira.
- The Piastre is still used in Mauritius when bidding in auction sales, similarly to the way that guineas are used at racehorse auctions. It is equivalent to 2 rupees.
Noted in pop group Steely Dan's song "Doctor Wu" -- "Just when I'd spent the last piastre I could borrow."