柯林斯詞典caustic soda 1. N-UNCOUNT Caustic soda is a powerful chemical substance used to make strong soaps and clean drains. 苛性鈉 返回 caustic soda劍橋詞典a caustic chemical used in industrial processes such as soap and paper production , and in powerful cleaning substances 苛性鈉，燒堿 返回 caustic soda