噬ぜい臍せい

noun

bitter regret

Archaic literary term for deep remorse, often over a missed opportunity or irreversible mistake. Found in classical Chinese-influenced texts.

• 「噬ぜい臍せい」は、臍ほぞを噬かむ、つまり自じ分ぶんのへそを噛かもうとしても届とどかないことから、取とり返かえしのつかない後こう悔かいを表あらわす古ふるい表ひょう現げんだ。

  「噬臍」 is an old expression meaning irreparable regret, from the image of trying to bite one's own navel but being unable to reach it.