hol ‧ o ‧ caust /ˈhɒləkɔːst $ ˈhɑːləkɒːst/ BrE AmE noun [countable]
[ Date: 1200-1300 ; Language: Old French ; Origin: holocauste , from Greek holokaustos 'burnt whole' , from holos 'whole' + kaiein 'to burn' ]
1 . a situation in which there is great destruction and a lot of people die:
a nuclear holocaust
2 . the Holocaust the killing of millions of Jews and other people by the Nazis during the Second World War ⇨ genocide