CATASTROPHE

Ca‐tas″tro‐phe (?), n. [[L. catastropha, Gr. �, fr. � to turn up and down, to overturn; κατά down + � to turn.]] 1. 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. 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. 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.