'bannerman' originates from English, specifically the compound of 'banner' and 'man', where 'banner' meant a flag or standard and 'man' meant a person.

'banner' comes from Old French 'baniere' (from Late Latin 'bandaria' or Medieval Latin influences) and 'man' from Old English 'mann'; the compound 'bannerman' developed in Middle to Modern English as the language used such compounds to denote a carrier of a banner.

Initially, it meant 'a man who bears a banner' and this core meaning has largely remained the same, later gaining occasional figurative use as 'a prominent supporter' and also becoming a surname.