What does "informer" mean?

Informer: One who informs, or imparts knowledge or news.

Additional senses

  1. 2.(Law) One who informs a magistrate of violations of law; one who informs against another for violation of some law or penal statute. Common informer (Law), one who habitually gives information of the violation of penal statutes, with a view to a prosecution therefor. Bouvier. Wharton.

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