'antu' originates from Mapudungun (the Mapuche language), specifically the word 'Antü' meaning 'sun'.

'Antü' (Mapudungun) was rendered in Spanish-language ethnographic texts as 'Antu' and then appears in English-language works on Mapuche mythology as 'Antu'.

Initially it directly named the sun or sun spirit in Mapudungun; in English usage it has been retained as the proper name of that sun deity or spirit.