Definição e Significado de "[keep] a civil tongue"

What is the origin of the idiom "keep a civil tongue" and when to use it?

The idiom "keep a civil tongue" has its origins in the idea of maintaining politeness and respectful communication, especially when discussing sensitive matters or engaging in conversations with others. It emphasizes the importance of using considerate and courteous language when interacting with people. This phrase is typically used to encourage or remind someone to speak with respect and good manners.