Origin and history of apocalypse

late 14c., "revelation, disclosure," from Church Latin apocalypsis "revelation," from Greek apokalyptein "uncover, disclose, reveal," from apo "off, away from" (see apo-) + kalyptein "to cover, conceal" (from PIE root *kel- (1) "to cover, conceal, save"). The Biblical story, sometimes interpreted as being about the end of the world, is part of the revelation in John of Patmos' book "Apokalypsis" (a title rendered into English as pocalipsis c. 1050, "Apocalypse" c. 1230, and "Revelation" by Wycliffe c. 1380). From this comes the sense "violent or horrific end of the world" by 1940. Mayan apocalypse, a belief that the world would end when the Mayan calendar ran out in 2012, is recorded by 1991.

Its general sense in Middle English was "insight, vision; hallucination." The general meaning "a cataclysmic event" is modern (not in OED 2nd ed., 1989); apocalypticism "belief in an imminent end of the present world" is from 1858. As agent nouns, "author or interpreter of the 'Apocalypse,' " apocalypst (1829), apocalypt (1834), and apocalyptist (1824) have been tried.

The majority of people who read the book of Revelation never ask about its historical context and literary genre, even though they know (at least implicitly) that these things radically affect a text’s meaning. When it comes to this book in particular, that is a terrible mistake. […] A number of ancient writings are very similar to it, such as 1 Enoch, 2 Baruch, 4 Ezra, the Shepherd of Hermas, the Apocalypse of Peter, and the Apocalypse of Paul. These, too, contain bizarre visions given to famous religious figures who learn the heavenly mysteries that can make sense of the puzzling realities of life on earth. Scholars have long understood this genre was in common use among Jews and Christians from 200 BCE to 200 CE. [Bart D. Ehrman, Armageddon: What the Bible Really Says About the End, 2023.]