Informant

An informant (also called an informer or, as a slang term, a "snitch", "rat", "stool pigeon" or "stoolie" )^[1] is a person who tells someone private information about other people. This information is often damaging to the other people. It is meant to be information that is secret. The information is normally about a person, group or organization. It is given to an agency, often a government or law enforcement agency. The term is normally used in the law-enforcement world. In law enforcement, informants are known as confidential human sources (CHS), or criminal informants (CI).

A person from the U.S. State Department thanks, and give payment to, a disguised informant. The informant's information wws about a terrorist in the Philippines

The term can also refer, in a bad way, to someone who tells information about others without their permission.^[2] The term is commonly used in politics, industry, entertainment, and academia.^[3][4]

In the United States, a confidential informant or "CI" is "any individual who provides useful and credible information to a law enforcement agency regarding felonious criminal activities and from whom the agency expects or intends to obtain additional useful and credible information regarding such activities in the future".^[5]