Definition of "Nantucket"

A resort island south of Cape Cod, Massachusetts, United States, formerly a major whaling port.  examples

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.  examples

Ellipsis of Nantucket County., a combined town and county that includes the island of Nantucket, along with Tuckernuck and Muskeget.  examples