不可同日而語 [ㄅㄨˋ ㄎㄜˇ ㄊㄨㄥˊ ㄖˋ ㄦˊ ㄩˇ; bu4 ke3 tong2 ri4 er2 yu3] lit. mustn't speak of two things on the same day (idiom); not to be mentioned in the same breath incomparable ◄ ►