Definition of the word rat out

The phrase "rat out" originated in the late 1800s, during the era of organized crime in America's urban areas. It was originally a slang term used in the underworld to describe the act of betraying one's associates or colleagues to law enforcement. The origins of the word "rat" can be traced back to the early 1800s, when it was used to describe someone who mysteriously disappeared, leaving behind their property and loved ones. This person was then presumed to have "ratted" on their own gang or community, or turned them in to the police in return for a reduced sentence. Over time, the term "rat" came to be associated with traitors and informers in criminal underworld circles. The phrase "rat out" was then coined as a way to describe the act of providing information to law enforcement authorities that could result in the arrest or imprisonment of one's criminal associates. Today, "rat out" is still commonly used as a slang term in criminal circles, as well as in everyday language to describe any act of betrayal or revealing of secrets. However, its origins and original usage remain closely tied to the world of organized crime and the history of American urban life in the late 1800s and early 1900s.