'duty-based' originates from the combination of 'duty' and 'based', where 'duty' comes from the Old French 'deu', meaning 'that which is owing', and 'based' from the Old French 'basse', meaning 'foundation'.

'duty' evolved from the Old French 'deu', and 'based' from the Old French 'basse', eventually forming the modern English term 'duty-based'.

Initially, 'duty' meant 'that which is owing', and 'based' meant 'foundation'. Over time, 'duty-based' evolved to mean 'relating to or based on duty or obligation'.