The Collaborative International Dictionary of English v.0.48:

Relevance \Rel"e*vance\ (r?l"?*vans), Relevancy \Rel"e*van*cy\
   (-van*s?), n.
   1. The quality or state of being relevant; pertinency;
      applicability.
      [1913 Webster]

            Its answer little meaning, little relevancy bore.
                                                  --Poe.
      [1913 Webster]

   2. (Scots Law) Sufficiency to infer the conclusion.
      [1913 Webster]

WordNet (r) 3.0 (2006):

relevancy
    n 1: the relation of something to the matter at hand [syn:
         relevance, relevancy] [ant: irrelevance,
         irrelevancy]