Peso is the name of the currency of various countries:

Spanish is spoken in all these countries. In Spanish, peso means weight. The main Spanish coin, was the "8 Reales" piece. This is the famous "Piece of Eight" and later became called the "Peso". The peso coin weighed 27 grams and was of 92% pure Silver. It was the template for the United States coins and one Silver-Dollars equaled exactly one Peso. The Spanish peso, circulated through out the American Colonies, and States. It continued to be legal tender, until they were demonetized in 1857

Portuguese-speaking Guinea-Bissau previously used pesos (GWP) prior to adopting the CFA franc (XAF) upon accession to the West African Economic and Monetary Union (UEMOA) on 1 May 1997.