Arauco, a southern province of Chili, divided into the three departments of Arauco, Laja, and Nacimiento; area, 13,500 sq. m.; pop. in 1868, 82,709, besides some 35,000 Indians. Capital, Arauco, on a bay of the same name, 300 m. S. of Valparaiso. This province was created by decree of Dec. 7, 1852; but the Araucanian Indians still maintain their independence in the interior.