Main Entry: apoc·a·lypse
Etymology: Middle English, revelation, Revelation, from Late Latin apocalypsis, from Greek apokalypsis, from apokalyptein to uncover, from apo- kalyptein to cover - more at Hell
Date: 13th century
1a: one of the Jewish and Christian writings of 200 B.C. to A.D. 150 marked by pseudonymity, symbolic imagery, and the expectation of an imminent cosmic cataclysm in which God destroys the ruling powers of evil and raises the righteous to life in a messianic kingdom
b capitalized: Revelation 3
2a: something viewed as a prophetic revelation
» Check out this excellent website on Apocalyptic Ideas in Old English Literature.