A pilaster is a rectangular support that resembles a flat column. The pilaster projects only slightly from the wall, and has a base, a shaft, and a capital. Greek Revival homes often have pilasters.
"The fluted pilaster, so prevalent in Burgundy and Provence, is not Byzantine--in fact, it is seldom, if ever, used in Byzantine architecture." - Frederick Moore Simpson, A History of Architectural Development (1909), p. 204.