Source : Webster's Revised Unabridged Dictionary (1913)

Reciprocity \Rec`i*proc"i*ty\, n. [Cf. F. r['e]ciprocit['e]. See
   {Reciprocal}.]
   1. Mutual action and reaction.

   2. Reciprocal advantages, obligations, or rights;
      reciprocation.

   {Reciprocity treaty}, or {Treaty of reciprocity}, a treaty
      concluded between two countries, conferring equal
      privileges as regards customs or charges on imports, or in
      other respects.

   Syn: Reciprocation; interchange; mutuality.

Source : WordNet®

reciprocity
     n 1: a relation of mutual dependence or action or influence [syn:
           {reciprocality}]
     2: mutual exchange of commercial or other privileges