大だい転てん換かんだいてんかんMeanings1noundrastic change; major turnaround; sea changeRefers to a fundamental, large-scale shift in direction, policy, or situation. Often used in business, politics, or social contexts.会かい社しゃは経けい営えい方ほう針しんの大だい転てん換かんを発はっ表ぴょうした