Catastrophe

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

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.