the final nail in the coffin
US /ðə ˈfaɪnl neɪl ɪn ðə ˈkɔfɪn/
UK /ðə ˈfaɪnl neɪl ɪn ðə ˈkɔfɪn/

1.
最后一根稻草, 致命一击
an event that causes the failure of something that had already been weakening
:
•
The company's latest scandal was the final nail in the coffin for its reputation.
公司最新的丑闻是其声誉的最后一根稻草。
•
His decision to quit was the final nail in the coffin for the struggling project.
他辞职的决定是这个陷入困境的项目的最后一根稻草。