心知肚明 xīnzhīdùmíng to be well aware Definitions Defs Origin Strokes Stroke Words Sentences Sents 心 xīn noun mind thought; intellect; the organ of thinking知 zhī verb to know to know; to be aware of; to realize or sense肚 dù mind the inner heart or mind明 míng verb to understand to understand; to know; to be clear about something