The term 'OLD PERUVIAN' is related to the INCA civilization, which was the largest empire in pre-Columbian America. The INCA Empire, which was centered in what is now Peru, was ruled by the INCA dynasty from the 12th century until the Spanish conquest in the 16th century. The term 'INCA' is a four-letter word that refers to the members of the INCA dynasty, while 'INCAN' is a five-letter word that refers to the people of the INCA Empire.