mac I. variant of mack II. \ˈmak\noun (-s) Usage: usually capitalized Etymology: from Mac-, Mc-, common patronymic prefix in many Scotch and Irish surnames : fellow — used informally to address a man whose name is unknown < look, Mac, I don't hear a word you're saying — Maritta Wolff > III. noun ormack\“\ (-s) Etymology: by shortening 1.Britain: mackintosh 2.: mackinaw IV. abbreviation 1. macadam 2. macerate