Source : Webster's Revised Unabridged Dictionary (1913)

Commemorative \Com*mem"o*ra*tive\, a.
   Tending or intended to commemorate. ``A sacrifice
   commemorative of Christ's offering up his body for us.''
   --Hammond.

         An inscription commemorative of his victory. --Sir G.
                                                  C. Lewis.

Source : WordNet®

commemorative
     adj : intended as a commemoration; "a commemorative plaque" [syn:
           {commemorating}]