1. U.S. Hist.the slave states of Delaware, Maryland, Kentucky, and Missouri, which refused to secede from the Union in 1860–61.
2. the U.S. states touching the Canadian border.
3. certain countries of central and northern Europe that border on the former Soviet Union and belonged to the Russian Empire: Finland, Poland (prior to 1940), Estonia, Latvia, and Lithuania.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.