What was the holocoust? And what did it mean?

The Holocaust, also referred to as the Shoah, was a genocide during World War II in which Nazi Germany, aided by its collaborators, systematically murdered some six million European Jews, around / and it ment destruction or slaughter on a mass scale, especially caused by fire or nuclear war.

The definition of a Holocaust is a mass destruction / slaughter, and the most common one happened during WW2 in Germany. It was when Hitler's movement put Jewish people into concentration camps, killing around 6 million.