pilaster, in architecture, upright supporting member, attached to and projecting slightly from the face of a wall and equipped with a base and capital like a column; also, a similar form used decoratively.
The pilaster in general follows the rules and proportions of the classic orders; it may be fluted or not, but usually has no entasis or taper.
In the Renaissance, the pilaster, used as a purely decorative device, was often paneled and ornamented.