The Collaborative International Dictionary of English v.0.48:

cross-reference \cross-reference\ n.
   a reference at one place in a work to information at another
   place in the same work.

   Syn: cross-index.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

cross-reference
    n 1: a reference at one place in a work to information at
         another place in the same work [syn: cross-reference,
         cross-index]