Plural of banister; a series of upright posts (balusters) connected by a rail, typically running alongside stairs to provide safety and support.
From the singular 'banister,' which is a shortened form of 'baluster,' itself deriving from Italian 'balaustro' and ultimately Greek 'balaustion' meaning pomegranate flower, because the balusters resembled the shape of pomegranate buds.
It's wild that the word for stair railings comes from pomegranate flowers—ancient Roman architects thought the decorative posts looked like those delicate buds, and that poetic observation got locked into our language for 2,000 years.
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