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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What’s in my basement.πŸ€πŸ€πŸ€πŸ€πŸ€πŸ€πŸ€πŸ€πŸ€πŸ€πŸ€πŸ€πŸ€πŸ€
Yo man that’s a huge rat

Yeah it’s prob from my basement
by AverageDude6900 July 16, 2020
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When someone’s acting like a fucking rat.
friend: i got a B on my math test
You: you’re a rat for that
by tapthatrat December 03, 2017
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Someone who tells the cops vital information that leads to an arrest of another person
that nigga cody ratted on joe we should fuck him up
by mikeykay October 29, 2006
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A snitch. A person who has ""tattled" on another person
That niggas a fuckin rat.
by KiStone 1000 February 05, 2003
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A rat is an annoying friend or person you love in your life. But they love to piss you off..."so they a rat".
Shut up you fvcking rat.... I love you tho.
by kenny_west360 April 17, 2016
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