1. (n.)World War II the war between the Axis and the Allies, beginning on Sept. 1, 1939, with the German invasion of Poland, and ending with the surrender of Germany on May 8, 1945, and of Japan on Aug. 14, 1945.
Definition of 'world war ii'
Princeton's WordNet
1. (noun)World War II, World War 2, Second World War a war between the Allies (Australia, Belgium, Bolivia, Brazil, Canada, China, Colombia, Costa Rica, Cuba, Czechoslovakia, Dominican Republic, El Salvador, Ethiopia, France, Greece, Guatemala, Haiti, Honduras, India, Iran, Iraq, Luxembourg, Mexico, Netherlands, New Zealand, Nicaragua, Norway, Panama, Philippines, Poland, South Africa, United Kingdom, United States, USSR, Yugoslavia) and the Axis (Albania, Bulgaria, Finland, Germany, Hungary, Italy, Japan, Rumania, Slovakia, Thailand) from 1939 to 1945