n. In architecture, an upright cylinder or pillar which forms a center from which the steps of a winding stair radiate, and supports their inner ends from the bottom to the top.n. In carpentry, the tall and more or less ornamental post at the head or foot of a stair, supporting a handrail.n. In engineering, a cylindrical pillar terminating the wing-wall of a bridge.n. In a ship, an upright timber which receives the tenons of the rails leading from the breastwork of the gangway.n. A new thing; a novelty.