Final answer:
The Nazi leaders referred to their genocidal plan as the "Final Solution," which resulted in the Holocaust and the murder of about 6 million Jews.
Step-by-step explanation:
The euphemism used by the Nazi leaders to refer to their plan of eliminating Jews and other groups from their territories during WWII was the "Final Solution". This plan resulted in the Holocaust, an atrocious genocide where systematic extermination methods such as mass shootings, gas chambers, and others were employed. This led to the murder of approximately 6 million Jews, along with millions of other victims including Roma, people with disabilities, and various political and social dissidents.