rueful

1. ADJ If someone is rueful, they feel or express regret or sorrow in a quiet and gentle way. 悲伤的; 悔恨的[文学性] [usu ADV with v]

He shook his head and gave me a rueful smile. 他摇了摇头，对我苦笑了一下。

2. ruefullyADV

He grinned at her ruefully. 他对她咧嘴一笑，表示遗憾。