'balustrade' originates from Italian, specifically the word 'balaustrata' (from 'balaustra'), where 'balaustra' referred to the pomegranate bud/flower and was used because a 'baluster' (the small column) resembled that shape.

'balustrade' entered English via French 'balustrade' and Italian 'balaustrata' (from Late Latin/Greek roots referring to the pomegranate bud), and developed into the modern English word 'balustrade'.

Initially, it meant 'a row of balusters' or 'a railing composed of balusters'; over time the term has retained that architectural sense and now also appears adjectivally (e.g. 'balustraded') to describe something provided with such a railing.