偷ㄊㄡtōu天ㄊㄧㄢtiān換ㄏㄨㄢˋhuàn日ㄖˋrì

比喻暗中改變事物的內容、性質。《群音類選·竊符記·如姬竊符》：「偷天換日，強似攜雲握雨。」也作「換日偷天」。似偷梁換柱﹑移花接木

英to engage in fraudulent activities (idiom), skulduggery, to hoodwink people, to cheat sb audaciously