突变理论 tūbiànlǐlùn catastrophe theory Origin Definitions Defs Strokes Stroke Words Sentences Sents 突变 突變 tūbiàn sudden change a sudden or unexpected change; a leap in development; often used in contrast to 渐变 jiànbiàn理论 理論 lǐlùn noun theory a system of ideas intended to explain something, especially one based on general principles independent of the thing to be explained; doctrine