'agreement-based' originates from the English word 'agreement' combined with the suffix '-based', where 'agreement' meant 'a negotiated and typically legally binding arrangement between parties as to a course of action'.

'Agreement' comes from the Old French word 'agreer', which means 'to please or satisfy', and 'based' is derived from the Old English 'bæse', meaning 'foundation'.

Initially, 'agreement' meant 'to please or satisfy', but over time it evolved into its current meaning of 'a negotiated arrangement'.