Definition & Meaning of "slip of the tongue"in English

What is the origin of the idiom "slip of the tongue" and when to use it?

The idiom "slip of the tongue" originated from the idea that speech is a deliberate act that requires conscious control, and that sometimes this control can be momentarily lost or "slip" due to various reasons. The phrase is commonly used to describe situations where someone says something embarrassing, inappropriate, or offensive by accident.