catastrophism: Meaning and Definition of

ca•tas•tro•phism

Pronunciation: (ku-tas'tru-fiz"um), [key]
— n. Geol.
  1. the doctrine that certain vast geological changes in the earth's history were caused by catastrophes rather than gradual evolutionary processes.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.