The portion of the European landmass that lies east of Germany and the Alps and west of the Ural Mountains. It includes the former Eastern bloc countries of Poland, the Czech Republic and Slovakia (formerly as Czechoslovakia), Hungary, Romania, and Bulgaria, as well as the Baltic republics of Estonia, Latvia, and Lithuania, and the former Soviet republics of Belarus and Ukraine, along with Russia west of the Urals.
Definition of Eastern Europe in US English:
Eastern Europe
proper noun
The portion of the European landmass that lies east of Germany and the Alps and west of the Ural Mountains. It includes the former Eastern bloc countries of Poland, the Czech Republic and Slovakia (formerly as Czechoslovakia), Hungary, Romania, and Bulgaria, as well as the Baltic republics of Estonia, Latvia, and Lithuania, and the former Soviet republics of Belarus and Ukraine, along with Russia west of the Urals.