刎ふん頸けいの友とも

expression, noun

sworn friend; inseparable friend

A classical Chinese-derived expression for a friend so close one would risk one's life for them. Literary and somewhat formal; not used in casual modern conversation.

• 彼かれとは刎ふん頸けいの友ともと呼よべる間あいだ柄がらだ。

  He and I are what you would call sworn friends.

• 戦せん場じょうで生せい死しを共ともにした二人ふたりは、まさに刎ふん頸けいの友ともだった。

  The two who faced life and death together on the battlefield were truly inseparable friends.