1. (

• World_War_I ,
• World_War_ ,
• Great_War ,
• First_World_War ,
• War_to_End_War

) 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 ;