noun
1. sometimes capitalized B&S
a. : a state (as Delaware, Maryland, Virginia, Kentucky, or Missouri) bordering on an antislavery state and favoring slavery before the Civil War
b. : a state (as Maryland, West Virginia, Kentucky, Missouri, Oklahoma, or Tennessee) just north of the Solid South and traditionally voting Democratic
c. : a state (as Montana or No. Dakota) bordering on Canada
2. : a small country (as Poland) bordering on a larger more powerful country ; especially : such a country lying between two larger more powerful countries : buffer state