D defs.my
Entry 2 senses Webster, 1913

Banister

/băn'-ĭs-tẽr/ · Ban·is·ter · IPA /ˈbænɪstɚ/
01 n. A baluster.
  1. 1.
    A baluster.
  2. 2.
    The balustrade of a staircase. Formerly used in this sense mostly in the plural, now mostly in the singular.
    “He struggled to ascend the pulpit stairs, holding hard on the banisters. Sir W. Scott.Sir W. Scott.