rueful
/ˈruːfəl/
adjective
- Feeling or showing sadness, regret, or pity, often in a gentle or slightly humorous way.
- His rueful expression told me he knew he had made a mistake.
- The coach let out a rueful laugh after the team lost by one point.
- She gave a rueful smile when she realized she had forgotten her keys again.
Antonyms