Cataclysmic/ˌkætəˈklɪzmɪk/ Definition 1 of 2Pro Tip 1/3Emotional Intensity Used to evoke strong feelings about the severity of an event. Witnesses described the hurricane's landfall as cataclysmic. Pro Tip 2/3Often Hyperbolic Sometimes exaggerates the impact when used in casual speech. Their defeat in the sports championship was described as cataclysmic. Pro Tip 3/3Extremes Only Appropriate for describing very large-scale disasters, not minor ones. A cataclysmic volcanic eruption would affect global climate.