banister /ˈbænɪstɚ/noun 2verb 2forms 3 noun2 •The rail on the side of a staircase that a person's hand holds onto.She slid down the wooden banister like a child.He grasped the banister as he climbed the stairs. •One of the vertical supports of such a handrail. verb2 •To construct a banister. •To act as a banister. formsbanistered · banistering · banisters