holocaust

Short definition from Wiktionary

Noun

1. 1
   An offering or sacrifice to a deity that is completely burned to ashes.
2. 2
   A complete or large offering or sacrifice.
3. 3
   Complete destruction by fire; also, the thing so destroyed.
4. 4
   Extensive destruction of a group of animals or (especially) people; a large-scale massacre or slaughter.
5. 5
   Alternative letter-case form of Holocaust (“the systematic mass murder (democide or genocide) of Jews (and, more broadly, of disabled people, homosexuals, Romanis, Slavs, and others) perpetrated by Nazi Germany shortly before and during World War II”); hence, the state-sponsored mass murder of a particular group of people in society.

Verb

1. 1
   To sacrifice (chiefly an animal) to be completely burned.
2. 2
   To destroy (something) completely, especially by fire.
3. 3
   To subject (a group of people) to a holocaust (mass annihilation); to destroy en masse.
4. 4
   Alternative letter-case form of holocaust (“subject to a mass annihilation; destroy en masse”).

Proper noun

1. 1
   The systematic mass murder (genocide) of six million Jews perpetrated by Nazi Germany shortly before and during World War II.
2. 2
   The systematic mass murder (democide) of somewhere between eleven and fourteen million people, namely six million Jews and from five to eight million others (including Romanis, Slavs, homosexuals, and people with physical and mental disabilities), perpetrated by Nazi Germany shortly before and during World War II.