The term PART OF WWII can be solved by the three letter word WAR. World WAR II was a global conflict that lasted from 1939 to 1945 and involved most of the world's nations, including all of the great powers. It was the most widespread WAR in history, with more than 100 million people serving in military units. The WAR resulted in the deaths of over 70 million people, making it the deadliest conflict in human history.