baluster

In architecture, a short pillar supporting a stair rail or a the coping of a parapet. Balusters are often circular in section, swelling near the base and rising in a concave curve to a narrow stem or neck.

A row of balusters is called a balustrade.

A shaped turning used as a vertical supporting member or leg of a table, chair, etc. Of variable shape but typically swelling out like a vase towards the base.

A similar shape of a ceramic item, usually of a vase.