1 definition by link1834

A person who exposes another person's wrongdoings for reasons other than moral outrage or to seek justice. Usually for personal gain, to avoid trouble themselves, or out of jealousy.

The word is sometimes misused by highly immoral people to describe all people who provide incriminating evidence against other people, simply because they dislike the idea of being exposed, and want to associate a negative word with people who expose immorality.
Grant exposed the other members of his gang so the cops would reduce his sentence. He's a rat.
by link1834 April 11, 2012
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