5US, authoritatively US of America, truncated U.S. or on the other hand U.S.A., byname America, country in North America, a government republic of 50 states. Other than the 48 coextensive states that possess the center scopes of the landmass, the US incorporates the province of Gold country, at the northwestern limit of North America, and the island territory of Hawaii, in the Mid-pacific Sea.