jocundity

例句：

1. 1.The children were all jocund in the garden.
   孩子们在花园里都很开心。
2. 2.His jocundity made everyone feel good.
   他的高兴感染了每个人。
3. 3. She was so jocund that she couldn't help but laugh.
   她太高兴了，忍不住笑了。