apocalypse

Short definition from Wiktionary

Noun

1. 1
   A revealing, especially a prophecy of, or the unfolding of, supernatural events.
2. 2
   A huge disaster; a cataclysmic event; destruction or ruin of large scope and scale.
3. 3
   The unveiling of events prophesied in the Revelation; the second coming and the end of life on Earth; global destruction.
4. 4
   The Book of Revelation.

Proper noun

1. 1
   The written account of a revelation of hidden things given by God to a chosen prophet.
2. 2
   Revelation (last book of the Bible, composed of twenty-two chapters, which narrates a vision of the end times).
3. 3
   Armageddon: the destructive end of the world.