The Collaborative International Dictionary of English v.0.48:

Bluntness \Blunt"ness\, n.
   1. Want of edge or point; dullness; obtuseness; lack of
      sharpness.
      [1913 Webster]

            The multitude of elements and bluntness of angles.
                                                  --Holland.
      [1913 Webster]

   2. Abruptness of address; rude plainness. "Bluntness of
      speech." --Boyle.
      [1913 Webster]

WordNet (r) 3.0 (2006):

bluntness
    n 1: the quality of being direct and outspoken; "the bluntness
         of a Yorkshireman"
    2: without sharpness or clearness of edge or point; "the
       dullness of the pencil made his writing illegible" [syn:
       dullness, bluntness] [ant: asperity, keenness,
       sharpness]