UNDERPINNINGS

Noun

underpinnings

plural of underpinning

Source: Wiktionary

UNDERPINNING

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.]

UNDERPIN

Un`der*pin", v. t. [imp. & p. p. Underpinned; p. pr. & vb. n. Underpinning.]

1. To lay stones, masonry, etc., under, as the sills of a building, on which it is to rest.

2. To support by some solid foundation; to place something underneath for support.

Source: Webster’s Unabridged Dictionary 1913 Edition