‘遗恨’ (yí hèn) is a formal, literary noun meaning a deep, lingering regret—often over something irreversible, such as an unfulfilled ambition, a missed opportunity, or a loss that leaves emotional residue. The first character 遗 (yí) means ‘to leave behind’ or ‘remaining’, and the second character 恨 (hèn) means ‘bitter regret’ or ‘deep resentment’. Together, they convey regret that persists long after the event has passed—something emotionally ‘left behind’ and never resolved.

This word carries strong emotional weight and is commonly found in classical poetry, historical narratives, biographies, and solemn speeches. It implies gravity and finality: not everyday disappointment, but profound sorrow tied to fate, duty, or moral failure. Because of its elevated register, it rarely appears in casual conversation and is more typical in written Chinese or formal oral contexts like memorial addresses or literary analysis.