Meaning: The grown-ups had fun talking and laughing among themselves.
Choice of Words: Adults are people who are fully grown, chatted means to talk in a friendly way, and laughed means to make sounds showing amusement.
Alternative Expressions
The grown-ups had a nice conversation and shared some jokes.
Meaning: This sentence is similar to the first one, but it uses different words to describe what the adults were doing. It still tells us that they were having a good time together.
Choice of Words: The word "grown-ups" also means adults. "Conversation" means they were talking to each other. "Shared some jokes" means they told each other funny stories or ideas that made them laugh.
The older people talked and chuckled together.
Meaning: This sentence is similar to the first two, but it uses different words to describe the adults and their actions. It still tells us that they were enjoying each other's company.
Choice of Words: The phrase "older people" is another way to say adults. "Talked" means they were having a conversation. "Chuckled" means they were making soft, happy sounds because they were amused.