Princeton's WordNet

1. holocaust(noun)

   an act of mass destruction and loss of life (especially in war or by fire)

   "a nuclear holocaust"

2. Holocaust, final solution(noun)

   the mass murder of Jews under the German Nazi regime from 1941 until 1945

Wiktionary

1. holocaust(Noun)

   A sacrifice to a god that is completely burned to ashes.

2. holocaust(Noun)

   The annihilation or near-annihilation of a group of animals or people, whether by natural or deliberate agency (e.g., u201Cnuclear holocaustu201D)

3. holocaust(Noun)

   The state-sponsored mass murder of an ethnic group. In particular (and often with an initial capital) the u201CFinal Solutionu201D, a euphemism used by the Nazis to describe the mass killing of Jews and others either in camps equipped with industrial gassing and crematorium equipment or by more conventional means.

4. Holocaust(ProperNoun)

   The mass murder of Jews and other groups by the Nazi regime during World War II.

Origin: From holocauste, from holocaustum, from the neuter form of ὁλόκαυστος, from ὅλος + καύστος, from καίω

Webster Dictionary

1. Holocaust(noun)

   a burnt sacrifice; an offering, the whole of which was consumed by fire, among the Jews and some pagan nations

2. Holocaust(noun)

   sacrifice or loss of many lives, as by the burning of a theater or a ship. [An extended use not authorized by careful writers.]

U.S. National Library of Medicine

1. Holocaust

   A massive slaughter, especially the systematic mass extermination of European Jews in Nazi concentration camps prior to and during World War II.

• slagtingAfrikaans
• مُحْرَقَه، كارثَه، إبادة كامِلَهArabic
• унищожениеBulgarian
• holocaustoPortuguese (BR)
• vyhlazeníCzech
• die MassenvernichtungGerman
• holocaust; masseudryddelseDanish
• ολοκαύτωμαGreek
• holocaustoSpanish
• suur häving, holokaustEstonian
• همه سوزیFarsi
• tuhoFinnish
• holocausteFrench
• שוֹאָהHebrew
• महाविनाशHindi
• opci pokolj, opce razaranjeCroatian
• holokausztHungarian
• malapetakaIndonesian
• brennifórn; fjöldamorð, þjóðarmorðIcelandic
• olocaustoItalian
• 大虐殺Japanese
• 대참사Korean
• masinis sunaikinimas/sudeginimasLithuanian
• holokausts, masveida iznīcināšanaLatvian
• kehancuranMalay
• vernietigingDutch
• katastrofebrannNorwegian
• zagładaPolish
• همه سوزیPersian
• سوځیدلPashto
• holocaustoPortuguese
• holocaustRomanian
• массовое уничтожение (людей)Russian
• úplné zničenie (ohňom), holokaustSlovak
• veliko razdejanje; holokavstSlovenian
• holokaustSerbian
• förödelse, katastrof, förhärjande brandSwedish
• ความหายนะThai
• mahvolma, tamamen yok olmaTurkish
• (常指大火造成的)大浩劫, 大屠殺Chinese (Trad.)
• знищення; масове винищенняUkrainian
• آگ وغیرہ سے زبردست تباہیUrdu
• sự tàn sátVietnamese
• 大毁灭，大屠杀Chinese (Simp.)