ARAUCANIA, a territory of South America, between lat. 37° and 39° 50' S., and long. 70° and 75° 20' W. It is bounded on the N. by the river Biobio, which separates it from Chili, S. by the Valdivia, E. by the Andes, and W. by the Pacific Ocean. See America, vol. i. p. 701, and Patagonia.