rigidness

from WordNet (r) 3.0 (2006)

rigidness
    n 1: the physical property of being stiff and resisting bending
         [syn: {rigidity}, {rigidness}]
    2: the quality of being rigid and rigorously severe [syn:
       {inflexibility}, {rigidity}, {rigidness}] [ant:
       {flexibility}, {flexibleness}]

from The Collaborative International Dictionary of English v.0.48

Rigidness \Rig"id*ness\, n.
   The quality or state of being rigid.
   [1913 Webster]