pilaster base

base block

1. A block of any material, generally with little or no ornament, forming the lowest member of a base, or itself fulfilling the functions of a base, as a member applied to the foot of a door or to window trim.
2. A rectangular block at the base of a casing or column which the baseboard abuts; usually slightly thicker than either the casing or baseboard.
References in periodicals archive ?
So when you frame and trim the pilaster base skirts, make sure everything fits loosely.
In New York, the predella panels and pilaster bases are reconstructed, but the predella and lunette are separated from the main panel.