confidential informant

American  

[kon-fi-den-shuhl in-fawr-muhnt] / ˌkɒn fɪˈdɛn ʃəl ɪnˈfɔr mənt /

noun

1. a person who works undercover for law enforcement to gather information about felonious criminal activities: some confidential informants are criminals themselves, hired to work undercover in exchange for leniency or exoneration: CI

   We’re told that this elusive drug lord was finally taken down thanks largely to a confidential informant, whose identity remains fiercely protected.

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Etymology

Origin of confidential informant

First recorded in 1940–45