- a state in the northern central United States: a part of the Midwest. 77,047 sq. mi. (199,550 sq. km). Capital: Pierre. Abbreviations: SD (for use with zip code), S. Dak.
- a state of the western US: lies mostly in the Great Plains; the chief US producer of gold and beryl. Capital: Pierre. Pop: 764 309 (2003 est). Area: 196 723 sq km (75 955 sq miles)
