n.; pl. Guanacos [ Sp. guanaco, Peruv. huanacu. Cf. Huanaco. ] (Zool.) A South American mammal (Auchenia huanaco), allied to the llama, but of larger size and more graceful form, inhabiting the southern Andes and Patagonia. It is supposed by some to be the llama in a wild state. [ Written also huanaco. ] [ 1913 Webster ]