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.

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.

• To support from below with props or masonry
       
• The mine roof was underpinned to prevent further collapse
  
• To give support to
       
• Public confidence in politicians must underpin our democracy