'bannerer' originates from English, specifically the word 'banner' with the agentive suffix '-er' (meaning 'one who carries or is associated with').

'banner' entered Middle English from Old French 'baniere' (modern French 'bannière'), which comes from Late Latin 'bandum'/'bandera' (a flag or sign); the English agentive formation produced 'bannerer' meaning 'one who bears a banner'.

Initially, the root 'banner' meant 'a flag or standard'; 'bannerer' originally meant strictly 'one who carries a banner.' Over time it has occasionally taken on a figurative sense meaning 'a leading advocate or champion of a cause.'