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.
  ◄ ►
  underpin
       v 1: support from beneath
       2: support with evidence or authority or make more certain or
          confirm; "The stories and claims were born out by the
          evidence" [syn: corroborate, bear out, support]
       [also: underpinning, underpinned]