wash something away
phrasal verb with wash verb uk/wɒʃ/ us/wɑːʃ/
（水或雨水）冲走，冲掉
If water or rain washes something away, it removes it or carries it away.
The blood on the pavement had been washed away by the rain overnight. 一夜之间，人行道上的血迹就被雨水冲掉了。