kiss of death
US /kɪs əv dɛθ/
UK /kɪs əv dɛθ/

1.
死亡之吻, 致命一击
an action or event that causes something to fail or come to an end
:
•
The new policy was the kiss of death for the small business.
这项新政策是小企业的死亡之吻。
•
His endorsement was the kiss of death for the struggling candidate.
他的支持对这位苦苦挣扎的候选人来说是死亡之吻。