1. an informal record; 2. a brief note, in writing, of some transaction; 3. an outline of an intended instrument; 4. an instrument written in concise summary MEMORANDUM OF LAW: an argument by an advocate in support of his or her position; like a brief but less formal. OFFICE MEMORANDUM: informal discussion of the merits of a matter pending in a lawyer's office; usually written by a law clerk or junior associate for a senior associate or partner. Source: Barron's Dictionary of Legal Terms, Steven H. Gifis, 5th Edition; © 2016