Source : Webster's Revised Unabridged Dictionary (1913)

Referential \Ref`er*en"tial\ (-shal), a.
   Containing a reference; pointing to something out of itself;
   as, notes for referential use. -- {Ref`er*en"tial*ly}, adv.

Source : WordNet®

referential
     adj : referring or pointing to something; "symbols are inherently
           referential"