pilaster

A rectangular column with a capital and base, projecting only slightly from a wall as an ornamental motif.

A square pillar, with its capital and base, projecting from a pier, or from a wall, to the extent of from one quarter to one third of its breadth; an engaged pillar.

An upright architectural member right-angled in plan, constructionally a pier (See pier, 1 (b)), but architecturally corresponding to a column, having capital, shaft, and base to agree with those of the columns of the same order. In most cases the projection from the wall is one third of its width, or less.

A rectangular column that projects partially from the wall to which it attached; it gives the appearance of a support, but is only for decoration.

a rectangular column that usually projects about a third of its width from the wall to which it is attached