a stool pigeon

a stool pigeon

a person, especially a criminal, who secretly gives information to the police in order to help them catch other criminals Once they discovered he was a stool pigeon, it was only a matter of time before they had him killed.
See also: pigeon, stool
References in periodicals archive ?
He's also a drugs baron and when she interrupts him in the process of rubbing out a stool pigeon, she has to run for her life.
Police believe the pigeon was meant to represent a stool pigeon - a term for a grass or snitch.
She told us she couldn't possibly say because she didn't want to be labelled a stool pigeon.
Another television teenager, Meadow Soprano, was lucky: Her dad dropped her off at Bates, Bowdoin, and Colby because he had to track down and murder a stool pigeon.
A contrasting love stow develops between Boss Whalen's new secretary, Eva (Sherri Parker Lee), and his in-house spy, Canary Jim (Finbar Lynch), who's despised as a stool pigeon by his fellow inmates but who uses his compromised position to break the prison scandal to the world.
The centerpiece of the EP is "Anna Is A Stool Pigeon," which Gabel wrote after reading about environmental activist Eric McDavid (www.