1) Correlation 2) Correlational 3) Correlativity 4) Interdependence 5) Interdependency 6) Mutuality 7) Mutualness 8) Reciprocity 1) Reciprocity 2) Relation 
• (n.) The quality or condition of being reciprocal; reciprocalness.
Re·cip`ro·cal'i·ty (-kăl'ĭ*tȳ) noun The quality or condition of being reciprocal; reciprocalness. [ R.]
[n] - a relation of mutual dependence or action or influence
reciprocality A relation of mutual dependence or action or influence.
reciprocity noun a relation of mutual dependence or action or influence