IPIRANGA is an affluent of the Tamanduateí river, on the left shore, in the city of São Paulo. Its bank is historically known as the place where Dom Pedro, then Prince Regent, later Emperor of Brazil, gave the cry of Independence of Brazil on September 7, 1822. Ipiranga is a corruption, or rather, a contraction of the word IPI-RÁ-Ã-N-GA meaning “sloping and uneven bed”. From y – relative; PI – centre, deep; RÁ – uneven, unequal; Ã – slope, with the suffix N G A (brief) to form the supine.
Source: BARRO, Máximo and BACELLI, Roney. Ipiranga – Series: História dos bairros (The History of neighbourhoods). Department of Historical Heritage – Historical Archive Division, 1979.