'Andes' originates from Spanish, specifically the word 'Andes', which is believed to derive from the Quechua word 'anti', meaning 'east' or 'high crest'.

'Andes' was adopted into English from Spanish explorers' reports, who used the local name for the mountain range, and it eventually became the modern English word 'Andes'.

Initially, it referred specifically to the eastern region or high mountains in the Quechua language, but over time it evolved into its current meaning of the entire mountain range along western South America.