In 1792 George Vancouver gave the name "Puget's Sound" to the waters south of the Tacoma Narrows, in honor of Peter Puget, a Huguenot lieutenant accompanying him on the Vancouver Expedition. This name later came to be used for the waters north of Tacoma Narrows as well.
The USGS defines Puget Sound as all the waters south of three entrances—the main entrance at Admiralty Inlet being a line between Point Wilson, on the Olympic Peninsula, and Point Partridge, on Whidbey Island; a second entrance at Deception Pass being a line from West Point, on Whidbey Island, to Deception Island and Rosario Head, on Fidalgo Island; and a third entrance at the south end of the Swinomish Channel, which connects Skagit Bay and Padilla Bay. Under this definition, Puget Sound includes the waters of Hood Canal, Admiralty Inlet, Possession Sound, Saratoga Passage, and others. It does not include Bellingham Bay, Padilla Bay, the waters of the San Juan Islands or anything farther north.
According to Arthur Kruckeberg, the term "Puget Sound" is sometimes used for waters north of Admiralty Inlet and Deception Pass, especially for areas along the north coast of Washington and the San Juan Islands, essentially equivalent to NOAA's "Northern Puget Sound" subdivision described above. Kruckeberg uses the term "Puget Sound and adjacent waters".
An alternative term for Puget Sound, still used by some Native Americans and environmental groups, is Whulge (or Whulj), an Anglicization of the Lushootseed name 'WulcH, which means "Salt Water". Since 2009 the term Salish Sea has been established by the United States Board on Geographic Names as the collective waters of Puget Sound, the Strait of Juan de Fuca, and the Strait of Georgia. Sometimes the terms "Puget Sound" and "Puget Sound and adjacent waters" are used for not only Puget Sound proper but also for waters to the north, such as Bellingham Bay and the San Juan Islands region.