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As to the origin of the name gaucho, there are again many theories which trace the word to everything from Arabic and Basque, to French and Portuguese. The most likely answer, however, is that the word has joint roots in the native Indian dialects of Que-chua and Mapuche, a derivation of their word for orphan (Huacho). It is not hard to imagine how a word meaning orphan evolved into a term for these solitary figures, as they were neither loved nor ruled by anyone. The first gauchos were mostly mestizos, of mixed Spanish and native American stock. As with the North American cowboy, some
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http://www.argentour.com/gente/gaucho.html