The Collaborative International Dictionary of English v.0.48:

Forthrightness \Forth"right`ness\, n.
   Straightforwardness; explicitness; directness. [Archaic]
   [1913 Webster]

         Dante's concise forthrightness of phrase. --Hawthorne.
   [1913 Webster]

WordNet (r) 3.0 (2006):

forthrightness
    n 1: the quality of being honest and straightforward in attitude
         and speech [syn: candor, candour, candidness,
         frankness, directness, forthrightness]