Source : Webster's Revised Unabridged Dictionary (1913)

Openness \O"pen*ness\, n.
   The quality or state of being open.

Source : WordNet®

openness
     n 1: without obstructions to passage or view; "the openness of
          the prairies"
     2: characterized by an attitude of ready accessibility
        (especially about one's actions or purposes); not
        secretive [ant: {closeness}]
     3: willingness or readiness to receive (especially impressions
        or ideas); "he was testing the government's receptiveness
        to reform"; "this receptiveness is the key feature is
        oestral behavior, enabling natural mating to occur";
        "their receptivity to the proposal" [syn: {receptiveness},
         {receptivity}]