'Informer' definitions:

Definition of 'informer'

(from WordNet)
noun
One who reveals confidential information in return for money [syn: informer, betrayer, rat, squealer, blabber]

Definition of 'Informer'

From: GCIDE
  • Informer \In*form"er\ ([i^]n*f[^o]rm"[~e]r), n. [From Inform, v.]
  • 1. One who informs, animates, or inspires. [Obs.] --Thomson. [1913 Webster]
  • Nature, informer of the poet's art. --Pope. [1913 Webster]
  • 2. One who informs, or imparts knowledge or news. [1913 Webster]
  • 3. (Law) One who informs a magistrate of violations of law; one who informs against another for violation of some law or penal statute. [1913 Webster]
  • Common informer (Law), one who habitually gives information of the violation of penal statutes, with a view to a prosecution therefor. --Bouvier. --Wharton. [1913 Webster]