'buoy' originates from Middle Dutch, specifically the word 'boeye', where 'boeye' meant 'a float'.

'boeye' transformed into the Old French word 'buie', and eventually became the modern English word 'buoy' through Middle English.

Initially, it meant 'a float or marker in water', but over time it evolved into its current meaning of 'to keep afloat or support'.