noun
finishing blow; coup de grâce
Used literally for a killing stroke, and figuratively for a decisive final action that ends something. Most common in the phrase とどめを刺す.
See also: とどめを刺す
彼は倒れた相手にとどめを刺した。
He dealt the finishing blow to his fallen opponent.
その一言が彼のキャリアにとどめを刺した。
That one remark was the final blow to his career.
The verb phrase meaning 'to deliver the finishing blow'; とどめ is the noun component.
Derived from the verb とどめる (to stop, to hold back), with the sense of stopping someone permanently. The exact historical development is uncertain.