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: Webster's Revised Unabridged Dictionary (1913)