I. noun 1. a short decorative pillar forming part of a series supporting a rail or coping. 2. [as modifier] — (of a furniture leg or other decorative item) having the form of a baluster • baluster legs in English oak.
– origin early 17th cent.: from French balustre, from Italian balaustro, from balaust(r)a ‘wild pomegranate flower’ (via Latin from Greek balaustion), so named because part of the pillar resembles the curving calyx tube of the flower.