/ˌræʃəˈnɑ:l ||; ˌræʃəˈnæl/noun [C] (formal 正式)the rationale (behind/for/of sth) the principles or reasons which explain a particular decision, course of action, belief, etc （某决定、行动、信念等的）原则，理由: What is the rationale behind these new exams? 干吗要进行这种新的考试？