Definitions for: Underpinning

Webster (1913) Definition: Un"der*pin`ning, n.
1. The act of one who underpins; the act of supporting by
stones, masonry, or the like.

2. (Arch.)
(a) That by which a building is underpinned; the material
and construction used for support, introduced beneath
a wall already constructed.
(b) The foundation, esp. of a frame house. [Local, U. S.]