The Collaborative International Dictionary of English v.0.48:

Interconnection \In`ter*con*nec"tion\, n.
   Connection between; mutual connection.
   [1913 Webster]

WordNet (r) 3.0 (2006):

interconnection
    n 1: a state of being connected reciprocally; "an
         interconnection between the two buildings" [syn:
         interconnection, interconnectedness]
    2: (computer science) the act of interconnecting (wires or
       computers or theories etc.)