An etymological theory suggests a Proto-Basque origin by the term "*nur" (stone) with the common "-ak" plural ending; the Paleo-Sardinian suffix -"ake", also found in some Indo-European languages such as Latin and Greek. Another possible explanation is that the term "nuraghe" came from the name of the Iberian mythological hero Norax, and the root "*nur" would be an adaptation of the Indo-European root "*nor".