Ūn'der-pĭn'ning, n.
n. 1. The act of one who underpins; the act of placing stones under sills. 2. That by which a building is underpinned; the stones on which a building immediately rests.
n. 1. The act of one who underpins; the act of placing stones under sills. 2. That by which a building is underpinned; the stones on which a building immediately rests.