'apocalypse' originates from Greek, specifically the word 'apokalypsis', where 'apo-' meant 'away, off' and 'kalypsis' (from 'kalyptō') meant 'a covering' or 'to cover'.

'apokalypsis' passed into Late Latin as 'apocalypsis', then into Old French and Middle English (forms like 'apocalips'/'apocalips(e)') before becoming the modern English 'apocalypse'.

Initially it meant 'uncovering' or 'revelation' (especially of divine truths). Over time, especially from readings of the biblical Book of Revelation, it evolved to often mean a cataclysmic end-of-world event or widespread destruction.