informer Meaning, Definition & Usage

  1. noun one who reveals confidential information in return for money
    squealer; rat; betrayer; blabber.

WordNet

In*form"er noun
Etymology
From Inform,v.
Definitions
  1. One who informs, animates, or inspires. Obs. Thomson.
    Nature, informer of the poet's art. Pope.
  2. One who informs, or imparts knowledge or news.
  3. (Law) One who informs a magistrate of violations of law; one who informs against another for violation of some law or penal statute.

Webster 1913