Webster's Revised Unabridged Dictionary · 1913

Pillar

Pillar , noun

[Old English pilerFrench pilier, Late Latin pilare, pilarium, pilarius, from Latin pila a pillar. See Pile a heap.]

1.
The general and popular term for a firm, upright, insulated support for a superstructure; a pier, column, or post; also, a column or shaft not supporting a superstructure, as one erected for a monument or an ornament.
Jacob set a pillar upon her grave. — Gen. xxxv. 20
The place... vast and proud, Supported by a hundred pillars stood. — Dryden
2.
Figuratively, that which resembles such a pillar in appearance, character, or office; a supporter or mainstay; as, the Pillars of Hercules; a pillar of the state.
You are a well-deserving pillar. — Shakespeare
By day a cloud, by night a pillar of fire. — Milton
3.
(Roman Catholic Church) A portable ornamental column, formerly carried before a cardinal, as emblematic of his support to the church. [Obsolete] — Skelton
4.
(Man.) The center of the volta, ring, or manege ground, around which a horse turns.
Collocations (3)
From pillar to post , hither and thither; to and fro; from one place or predicament to another; backward and forward. [Colloquial]
Pillar saint , See Stylite.
Pillars of the fauces , See Fauces, 1.

Pillar , adjective

(Machinery) Having a support in the form of a pillar, instead of legs; as, a pillar drill.