ûi-hūn遺恨

eternal regret

eternal regret; to eternally regret; to feel remorseful or unsatisfied upon death

English Wiktionary, “遺恨” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E9%81%BA%E6%81%A8 · confidence: Medium (Wiktionary, Hokkien)