無ㄨˊwú功ㄍㄨㄥgōng而ㄦˊér返ㄈㄢˇfǎn

  1. 沒達致預期功效而折回。如：「警方佈署不週，遭綁匪識破，無功而返。」

英to return without any achievement (idiom)​; to go home with one's tail between one's legs