'balbusard' originates from Old French, specifically the word 'balbuzard' (used for the osprey); the exact ultimate root is uncertain but it has often been linked to Latin 'balbus' meaning 'stammering' (perhaps a reference to the bird's cry).

'balbuzard' in Old French passed into Middle English/early modern English forms such as 'balbusard' and has been used in English as a name for the osprey (Pandion haliaetus).

The term has long referred to the same bird species (the osprey); its sense as a name for this fish-eating hawk has been stable over time.