Pillar, in architecture and building construction, any isolated, vertical structural member such as a pier, column, or post. It may be constructed of a single piece of stone or wood or built up of units, such as bricks. It may be any shape in cross section. A pillar commonly has a load-bearing or stabilizing function, but it may also stand alone, as do commemorative pillars. See alsocolumn.
in architecture, a vertical element, usually a rounded shaft with a capital and a base, which in most cases serves as a support. A column may also be nonstructural, used for a decorative purpose or as a freestanding monument.