activity by a military or naval force (as a maneuver or campaign)

a battle in the Meuse-Argonne operation in World War I (1918); the battle in which American troops launched their first offensive in France

a war between the allies (Russia, France, British Empire, Italy, United States, Japan, Rumania, Serbia, Belgium, Greece, Portugal, Montenegro) and the Central Powers (Germany, Austria-Hungary, Turkey, Bulgaria) from 1914 to 1918

a republic in western Europe; the largest country wholly in Europe

a battle in the Meuse-Argonne operation in World War I (1918); the battle in which American troops launched their first offensive in France

a war between the allies (Russia, France, British Empire, Italy, United States, Japan, Rumania, Serbia, Belgium, Greece, Portugal, Montenegro) and the Central Powers (Germany, Austria-Hungary, Turkey, Bulgaria) from 1914 to 1918

a republic in western Europe; the largest country wholly in Europe