English to English

noun (n)

• a sudden violent change in the earth's surface(noun.phenomenon)

  Synonym:
  catastrophe
  

  source: wordnet30
• an event resulting in great loss and misfortune(noun.event)

  Synonym:
  calamity, catastrophe, disaster, tragedy
  

  source: wordnet30
• An extensive overflow or sweeping flood of water; a deluge.(noun)

  source: webster1913