underpinning

Material or masonry used to support a structure, such as a wall.

A support or foundation.

The human legs.

The act of one who underpins; the act of supporting a superior part of a wall, etc., by introducing a support underneath it.

A solid structure, as a new foundation or other support, temporary or permanent, introduced beneath a wall, a building, etc., previously constructed, as when the original foundation has proved insufficient, or has been impaired from any cause. Also called undersetting, and in Scotland goufing.