[yí hàn]
regret; pity; regretful; sorry; repentant
express regret over the matter
对此表示遗憾
point out with great [deep] regret
十分遗憾地指出
a lifelong regret
终身遗憾
I am very sorry I won't be able to go.
很遗憾， 我不能去。
The Chinese Government regrets your action.
中国政府对你方采取的行动表示遗憾。