Source : WordNet®

World War I
     n : 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 [syn: {World War 1}, {Great War}, {First World War},
          {War to End War}]