Source : Webster's Revised Unabridged Dictionary (1913)

Memorandum \Mem`o*ran"dum\, n.; pl. E. {Memorandums}, L.
   {Memoranda}. [L., something to be remembered, neut. of
   memorandus, fut. pass. p. of memorare. See {Memorable}.]
   1. A record of something which it is desired to remember; a
      note to help the memory.

            I . . . entered a memorandum in my pocketbook.
                                                  --Guardian.

            I wish you would, as opportunity offers, make
            memorandums of the regulations of the academies.
                                                  --Sir J.
                                                  Reynolds.

   2. (Law) A brief or informal note in writing of some
      transaction, or an outline of an intended instrument; an
      instrument drawn up in a brief and compendious form.

   {Memorandum check}, a check given as an acknowledgment of
      indebtedness, but with the understanding that it will not
      be presented at bank unless the maker fails to take it up
      on the day the debt becomes due. It usually has Mem.
      written on its face.

Source : WordNet®

memorandum
     n : a written proposal or reminder [syn: {memo}, {memoranda}]
     [also: {memoranda} (pl)]