Cataclysm

Definition

• Def: Cataclysm 1. any violent upheaval, esp. one of a social or political nature; 2. Physical Geography. a sudden and violent physical action producing changes in the earth's surface; 3. an extensive flood; deluge; 4. a violent upheaval that causes great destruction or brings about a fundamental change;
  
  

• Origin: 1633, from Fr. cataclysme, from L. cataclysmos, from Gk. kataklysmos, from kata "down" + klyzein "to wash.";
  
  

• Synonyms: calamity, cataract, catastrophe, collapse, convulsion, debacle, deluge, disaster, disturbance, flood, flooding, inundation, misadventure, overflow, torrent, tragedy, upheaval, woe.

Source: Dictionary.com Unabridged