'archosaur' originates from Greek, specifically the words 'arkhos' meaning 'chief' or 'ruler' and 'sauros' meaning 'lizard'.

'archosaur' was derived from the Greek words 'arkhos' and 'sauros', and eventually became the modern English word 'archosaur'.

Initially, it meant 'ruling lizard', but over time it evolved into its current meaning of a group of reptiles including dinosaurs and modern birds.