an instance of wholesale destruction or loss of life
the nuclear holocaust
(the Holocaust) the genocidal persecution of European Jewry by Hitler and the Nazi party during World War II
formerly, in Jewish religious practice, a sacrificial offering wholly consumed by fire on the altar; = burnt offering (1)
[Middle English via Old French and late Latin from Greek holokauston, neuter of holokaustos burned whole, from holo- + kaustos burned, from kaiein to burn]