Pronunciation: (pil'ur),[key] —n. 1. an upright shaft or structure, of stone, brick, or other material, relatively slender in proportion to its height, and of any shape in section, used as a building support, or standing alone, as for a monument: Gothic pillars; a pillar to commemorate Columbus. 2. a natural formation resembling such a construction: a pillar of rock; a pillar of smoke. 3. any upright, supporting part; post: the pillar of a table. 4. a person who is a chief supporter of a society, state, institution, etc.: a pillar of the community. 5. Horol.any of several short parts for spacing and keeping in the proper relative positions two plates holding the bearings of a watch or clock movement.
6. Mining.an isolated mass of rock or ore in a mine, usually serving as a roof support in early operations and later removed, wholly or in part.
7. Naut.mast1 (def. 2).
8. from pillar to post, a. aimlessly from place to place.
b. uneasily from one bad situation or predicament to another.