1. a short plaid coat made of made of thick woolen material (Freq. 1) • Syn: Mackinaw coat • Hypernyms: coat 2. a thick plaid blanket formerly used in the northwestern United States • Syn: Mackinaw blanket • Hypernyms: blanket, cover 3. a flat-bottomed boat used on upper Great Lakes • Syn: Mackinaw boat • Hypernyms: boat 4. a heavy woolen cloth heavily napped and felted, often with a plaid design • Hypernyms: fabric, cloth, material, textile