a state in the central United States. 4,917,444; 69,674 sq. mi. (180,455 sq. km). Cap.: Jefferson City. Abbr.: MO (for use with zip code), Mo.
a river flowing from SW Montana into the Mississippi N of St. Louis, Mo. 2723 mi. (4382 km) long.
a member of a North American Indian tribe belonging to the Siouan linguistic stock, located on the Missouri River in early historic times and now extinct as a tribe.
unwilling to accept something without proof; skeptical: I'm from Missouri--you'll have to show me that you're right.