apocalyptic (adj.)

1660s, "pertaining to the 'Revelation of St. John' in the New Testament," from Greek apokalyptikos, from apokalyptein "uncover, disclose, reveal" (see apocalypse). The original general sense was "prophetic" (1680s); meaning "pertaining to the imminent end of the world" is attested by 1864. Related: Apocalyptical (1630s).