Source : Webster's Revised Unabridged Dictionary (1913)

Substantialness \Sub*stan"tial*ness\, n.
   The quality or state of being substantial; as, the
   substantialness of a wall or column.

Source : WordNet®

substantialness
     n : the quality of being substantial or having substance [syn: {substantiality}]
         [ant: {insubstantiality}]