Source : Webster's Revised Unabridged Dictionary (1913)

Memorial \Me*mo"ri*al\, a. [F. m['e]morial, L. memorialis, fr.
   memoria. See {Memory}.]
   1. Serving to preserve remembrance; commemorative; as, a
      memorial building.

            There high in air, memorial of my name, Fix the
            smooth oar, and bid me live to fame.  --Pope.

   2. Contained in memory; as, a memorial possession.

   3. Mnemonic; assisting the memory.

            This succession of Aspirate, Soft, and Hard, may be
            expressed by the memorial word ASH.   --Skeat.

   {Memorial Day}. Same as {Decoration Day}. [U.S.]

Memorial \Me*mo"ri*al\, n. [Cf. F. m['e]morial.]
   1. Anything intended to preserve the memory of a person or
      event; something which serves to keep something else in
      remembrance; a monument. --Macaulay.

            Churches have names; some as memorials of peace,
            some of wisdom, some in memory of the Trinity
            itself.                               --Hooker.

   2. A memorandum; a record. [Obs. or R.] --Hayward.

   3. A written representation of facts, addressed to the
      government, or to some branch of it, or to a society,
      etc., -- often accompanied with a petition.

   4. Memory; remembrance. [Obs.]

            Precious is the memorial of the just. --Evelyn.

   5. (Diplomacy) A species of informal state paper, much used
      in negotiation.

Source : WordNet®

memorial
     n 1: a recognition of meritorious service [syn: {commemoration},
          {remembrance}]
     2: a written statement of facts submitted in conjunction with a
        petition to an authority
     3: a structure erected to commemorate persons or events [syn: {monument}]