informant

American  

[in-fawr-muhnt] / ɪnˈfɔr mənt /

noun

1. a person who informs or gives information; informer.

   Synonyms:

   tipster, adviser, source

2. a person who supplies social or cultural data in answer to the questions of an investigator.

3. Linguistics. a native speaker of a language who supplies utterances and forms for one analyzing or learning the language.

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informant British  

/ ɪnˈfɔːmənt /

noun

1. a person who gives information about a thing, a subject being studied, etc

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Etymology

Origin of informant

1655–65; < Latin infōrmant- (stem of infōrmāns ) present participle of infōrmāre. See inform ¹, -ant

Explanation

An informant is someone who secretly provides information to police, the FBI, or another law enforcement agency. If you watch a lot of crime shows on TV, you're probably familiar with informants. In the world of law enforcement, informants are officially called CIs, for "confidential informant" or "criminal informant." The information informants provide can be useful in catching criminals, and the informant usually gets something in return — money or a reduced prison sentence, for example. Sometimes informant simply means "person who gives information."

Example Sentences

Columnist Clarence Page writes that “a key question will be whether prosecutors can distinguish SPLC’s informant practices from those long used by law enforcement.”

From The Wall Street Journal • Apr. 30, 2026

Only recently has Tennessee acknowledged that it used a paid informant.

From Slate • Apr. 20, 2026

To convict him, the state relied on the testimony of a paid jailhouse informant, while no physical evidence suggested he was present at the crime scene.

From Slate • Apr. 20, 2026

Victims of the extortion racket include two women who were arrested last month after a police informant said he had seen them kissing in the northern Ugandan city of Arua.

From The Wall Street Journal • Mar. 22, 2026

It was someone whom the agents knew all too well: Kelsie Morrison, their undercover informant who had supposedly been working with the agents to identify the third man.

From "Killers of the Flower Moon" by David Grann