type of boat used on the Great Lakes, 1812, from Mackinac, name of a port and island in Michigan, from Ojibway (Algonquian) mitchimakinak "many turtles," from mishiin- "be many" + mikinaak "snapping turtle." As a type of heavy blanket given to the Indians by the U.S. government, it is attested from 1822.[Mackinaw etymology, Mackinaw origin, 英语词源]