feeling or showing that you are sad or sorry 悲伤的;懊悔的;沮丧的 a rueful smile 惨然一笑
Oxford Collocations DictionaryRueful is used with these nouns:- grin
- laugh
- smile
- …
Word OriginMiddle English (also in the sense ‘pitiable’): from the noun rue ‘regret’ + -ful.