1.  openness(n = noun.attribute) - without obstructions to passage or view; "the openness of the prairies"
is a kind of spacing, spatial arrangement
has particulars: patency
Derived form adjective open₁₉

2.  openness(n = noun.attribute) nakedness - characterized by an attitude of ready accessibility (especially about one's actions or purposes); without concealment; not secretive;
is a kind of sociability, sociableness
Antonym: closeness
Derived forms adjective open₂₀, adjective open₁₆

3.  openness(n = noun.attribute) receptiveness, receptivity - willingness or readiness to receive (especially impressions or ideas); "he was testing the government's receptiveness to reform"; "this receptiveness is the key feature in oestral behavior, enabling natural mating to occur"; "their receptivity to the proposal"
is a kind of willingness
Derived forms adjective open₁₄, adjective open₁₅

   The quality or state of being open. [1913 Webster]