pilaster

noun Architecture.

1. a shallow rectangular feature projecting from a wall, having a capital and base and usually imitating the form of a column.

noun

1. a shallow rectangular column attached to the face of a wall

n.a square column, 1570s, from Middle French pilastre (1540s), from Italian pilastro, from Medieval Latin pilastrum (mid-14c.), from pila, “buttress, pile” (from Latin pila, see pillar) + Latin -aster, suffix “expressing incomplete resemblance” [Barnhart].