Cataclysm/ˈkætəklɪzəm/ Definition 1 of 3Pro Tip 1/3Massive Impact Used to describe events that dramatically alter life or landscape. The asteroid collision was a cataclysm, changing Earth's environment forever. Pro Tip 2/3Negative Connotation Implies harmful outcomes, not just any big change. War is often a cataclysm, leaving devastation in its wake. Pro Tip 3/3Not Always Literal Can be metaphorical, referring to events that feel like disasters. Her sudden resignation was a cataclysm for the company's morale.