The Aché are also known as the Axe people [REF].
The earliest published reports (Lozano 1873-74 summary of Jesuit accounts in the 17th century)[REF] about the Aché refer to them as "Guajagui", a term based on the Guaraní root "Guaja" (= enemy tribe, or brother-in-law) and "gui" a common Aché suffix (meaning "essence of" or "having the property of").