In classical architecture, a square pillar, sometimes standing free, but
usually attached to a wall, from which it projects one-fifth, one quarter,
or some other definite proportion of its breadth. Greek pilasters, or antae,
were of the same breadth from top to bottom, and had different capitals
and bases from those of the orders with which they were associated. The
Romans gave them a taper like the columns, and the same capitals and bases.