noun

• A resort island south of Cape Cod, Massachusetts, United States, formerly a major whaling port.
• A census-designated place in the north-middle part of Nantucket in Nantucket County, Massachusetts, comprising about 12% of the land area of the island.
• Ellipsis of Nantucket County., a combined town and county that includes the island of Nantucket, along with Tuckernuck and Muskeget. [one of 14 counties in Massachusetts, USA, located on the island of Nantucket and two other islands. It is coterminous with the town of Nantucket, and is known as the Town and County of Nantucket.]