Definitions

1. 1. lit. mustn't speak of two things on the same day (idiom)
2. 2. not to be mentioned in the same breath
3. 3. incomparable

Components

• 不可 bù kě – cannot
• 同日而语 tóng rì ér yǔ – lit. to speak of two things on the same day (idiom); to mention things on equal terms (often with negatives: you can't mention X at the same time as Y)