'argenteous' originates from Latin, specifically the word 'argentum', where 'argent-' meant 'silver'. It entered English via Late Latin and Old French forms (e.g. 'argenteus').

'argenteous' developed from Latin 'argentum' → Medieval/Late Latin 'argenteus' → Old French/Anglo-French 'argenteus' and was adopted into English as 'argenteous'.

Initially it meant 'of or relating to silver (the metal)', and over time it has come to mean more broadly 'silvery; resembling silver' in appearance or sheen.