\▐ba-lә-stәr\ n [Fr balustre, fr. It balaustro, fr. balaustra wild pomegranatye flower, fr. L balaustium, fr. Gk balaustion; fr. its shape] (1602) (1) One of a number of short vertical members, often circular in section, used to support a stair handrail or a coping. (2) A post in a balustrade. Also called Banister.