The Collaborative International Dictionary of English v.0.48:

Harshness \Harsh"ness\, n.
   The quality or state of being harsh.
   [1913 Webster]

         O, she is
         Ten times more gentle than her father's crabbed,
         And he's composed of harshness.          --Shak.
   [1913 Webster]

         'Tis not enough no harshness gives offense,
         The sound must seem an echo to the sense. --Pope.

   Syn: Acrimony; roughness; sternness; asperity; tartness. See
        Acrimony.
        [1913 Webster]

WordNet (r) 3.0 (2006):

harshness
    n 1: the roughness of a substance that causes abrasions [syn:
         harshness, abrasiveness, scratchiness]
    2: the quality of being unpleasant (harsh or rough or grating)
       to the senses [syn: harshness, roughness]
    3: the quality of being cruel and causing tension or annoyance
       [syn: cruelty, cruelness, harshness]
    4: excessive sternness; "severity of character"; "the harshness
       of his punishment was inhuman"; "the rigors of boot camp"
       [syn: severity, severeness, harshness, rigor,
       rigour, rigorousness, rigourousness, inclemency,
       hardness, stiffness]