the final nail in the coffin

US /ðə ˈfaɪnl neɪl ɪn ðə ˈkɔfɪn/
UK /ðə ˈfaɪnl neɪl ɪn ðə ˈkɔfɪn/
"the final nail in the coffin" picture
1.

결정타, 마지막 못

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.
회사의 최근 스캔들은 명성에 결정타였다.
His decision to quit was the final nail in the coffin for the struggling project.
그의 사임 결정은 어려움을 겪던 프로젝트에 결정타였다.