rat (one) out

rat (one) out

To inform an authority figure of one's bad or illegal behavior. I can't believe you ratted me out like that to Mom and Dad—I'm never telling you anything ever again! The criminal ratted out his accomplices to avoid jail time.
See also: out, rat
Farlex Dictionary of Idioms.

rat out

Sl. to quit; to fink out (on someone or something). It's too late to rat out. He tried to rat out at the last minute.
See also: out, rat
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

rat out

v.
To expose or reveal incriminating or embarrassing information about someone: The newspapers ratted out the people who were involved with the scam.
See also: out, rat
The American Heritage® Dictionary of Phrasal Verbs.

rat out

in. to quit; to fink out (on someone/something). He tried to rat out at the last minute.
See also: out, rat
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • rat on
  • rat on (one)
  • rat on someone
  • rat out
  • ratted
  • going to tell
  • tattle
  • going to tattle
  • grass on (one)
  • grasse