sing like a canary(redirected from sung like a canary)
sing like a canary
To inform against someone to the police or other authority about their criminal or illicit behavior. I heard Joey Malone has been singing like a canary in the hopes of getting his sentence reduced. Let's make sure he's sleeping with the fishes before he gets the chance!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.