A region of northwest Europe comprising Belgium, the Netherlands, and Luxembourg. another name for the Netherlands, a country in northwestern Europe, bordered by Belgium, Germany and the North Sea. It is called the Low Countries because the land is mostly flat, and some parts are below sea level. Coastal region, northwestern Europe, consisting of Belgium, The Netherlands, and Luxembourg. Known as the Low Countries because much of the land along the North Sea is below or at sea level, they are often called the Benelux countries, from the initial letters of their names