holocaust

noun
ho·​lo·​caust | \ ˈhō-lə-ˌkȯst How to pronounce holocaust (audio) , ˈhä- also -ˌkäst or ˈhȯ-lə-kȯst\

Definition of holocaust

1 : a sacrifice (see sacrifice entry 1 sense 2) consumed by fire
2 : a thorough destruction involving extensive loss of life especially through fire a nuclear holocaust
3a usually the Holocaust : the mass slaughter of European civilians and especially Jews by the Nazis during World War II Several members of her family died in the Holocaust. a Holocaust survivor
b : a mass slaughter of people especially : genocide a holocaust in Rwanda