adj.心情愉快的；无忧无虑的
The children looks lighthearted after the final exam. 期终考试结束了，孩子们看上去都很轻松愉快。
He leans towards more lighthearted subjects in his later works. 他在后期的创作中倾向于比较轻松的主题。
She was annoyed at his lighthearted attitude. 他对她那种若无其事的态度感到很生气。
Lighthearted youngsters were singing as they hiked through the woods. 无忧无虑的年轻人唱着歌步行穿过树林。
