Here's a breakdown:
* Rat: This is slang for a person who informs on others, particularly to authorities. It has a negative connotation, implying someone is disloyal and untrustworthy.
* You: This refers to the person being betrayed.
* Out: This indicates that the information is being revealed or exposed to others.
Example:
"If you tell the teacher I cheated on the test, you're going to rat me out!"
Other phrases with similar meanings:
* Snitch
* Tell on
* Grass on
* Blow the whistle on
Note: The term "rat you out" is generally used in a negative context and implies that the betrayal is harmful or unfair to the person being betrayed.