Source : Webster's Revised Unabridged Dictionary (1913)

Catastrophe \Ca*tas"tro*phe\, n. [L. catastropha, Gr. ?, fr. ?
   to turn up and down, to overturn; kata` down + ? to turn.]
   1. An event producing a subversion of the order or system of
      things; a final event, usually of a calamitous or
      disastrous nature; hence, sudden calamity; great
      misfortune.

            The strange catastrophe of affairs now at London.
                                                  --Bp. Burnet.

            The most horrible and portentous catastrophe that
            nature ever yet saw.                  --Woodward.

   2. The final event in a romance or a dramatic piece; a
      denouement, as a death in a tragedy, or a marriage in a
      comedy.

   3. (Geol.) A violent and widely extended change in the
      surface of the earth, as, an elevation or subsidence of
      some part of it, effected by internal causes. --Whewell.

Source : WordNet®

catastrophe
     n 1: an event resulting in great loss and misfortune; "the whole
          city was affected by the irremediable calamity"; "the
          earthquake was a disaster" [syn: {calamity}, {disaster},
           {tragedy}, {cataclysm}]
     2: a state of extreme (usually irremediable) ruin and
        misfortune; "lack of funds has resulted in a catastrophe
        for our school system"; "his policies were a disaster"
        [syn: {disaster}]
     3: a sudden violent change in the earth's surface [syn: {cataclysm}]