'bannister' originates from Middle English, specifically the word 'banester', where it referred to a 'baluster' or supporting post of a railing.

'bannister' changed from Middle English 'banester', under influence from Old French/Italian terms for turned supports (related to Old French 'balustre' and Italian 'balaustra'), and eventually became the modern English 'bannister'.

Initially, it meant 'a turned or ornamental support (a baluster)'; over time it evolved to refer to the handrail and often the whole railing assembly.