ban ‧ is ‧ ter /ˈbænəstə, ˈbænɪstə $ -ər/ BrE AmE noun [countable]
[ Date: 1600-1700 ; Origin: baluster 'one of the sticks of a banister' (17-21 centuries) , from French balustre , from Italian balaustro ; ⇨ ↑ balustrade ]
a row of wooden posts with a bar along the top, that stops you from falling over the edge of stairs