beat a dead horse
成語所屬單字beat
beat a dead horse — 慣用語
1. To waste effort on something that cannot succeed or change.
1.慣用語
釋義
白費力氣
To waste effort on something that cannot succeed or change.
例句
Arguing with him is beating a dead horse; he won't listen.
Stop beating a dead horse and move on to a new idea.