| Noun | 1. | Benelux - a customs union comprising Belgium and Netherlands and Luxembourg customs union - an association of nations to promote free trade within the union and set common tariffs for nations that are not members Belgique, Belgium, Kingdom of Belgium - a monarchy in northwestern Europe; headquarters for the European Union and for the North Atlantic Treaty Organization Holland, Kingdom of The Netherlands, Nederland, Netherlands, The Netherlands - a constitutional monarchy in western Europe on the North Sea; half the country lies below sea level Grand Duchy of Luxembourg, Luxembourg, Luxemburg - a grand duchy (a constitutional monarchy) landlocked in northwestern Europe between France and Belgium and Germany; an international financial center |