Meanings
historical · plural · plural onlythe pre-1938 territories of the German Reich east of the Oder-Neisse line, from where the German population was expelled after World War II, and which are now parts of Poland and Russia
plural · plural onlythe even vaster pre-1918 territories of the Reich as well as, possibly, the Sudetenland, which was German between 1938 and 1945 (areas conquered during WWII are never included)