noun (n)

• without obstructions to passage or view(noun.attribute)

  Example:
  The openness of the prairies.
  

  source: wordnet30
• characterized by an attitude of ready accessibility (especially about one's actions or purposes); without concealment; not secretive(noun.attribute)

  Synonym:
  nakedness
  Antonym:
  closeness, secretiveness
  

  source: wordnet30
• willingness or readiness to receive (especially impressions or ideas)(noun.attribute)

  Synonym:
  receptiveness, receptivity
  

  source: wordnet30
• The quality or state of being open.(noun)

  source: webster1913