The word stool pigeon has an interesting origin and evolution in meaning. We will look at the definition of the term stool pigeon, where it comes from and how its meaning has changed, as well as some examples of its current use in sentences.
A stool pigeon is someone who is an informer for the police. The term first appeared in the early 1800s to mean a decoy pigeon. The word stool in the term stool pigeon comes from the sixteenth-century word stoale, which means tree stump. Presumably, the term stoale pigeon referred to a decoy pigeon that was affixed to a tree stump. By the 1800s the word stool pigeon referred to a person who was used in a sting operation to trap a criminal, a sort of human decoy. By the turn of the twentieth century, the term stool pigeon was used in American English to mean somebody who is an informant concerning a crime, usually a co-criminal who gives authorities information concerning a crime in exchange for his freedom. Stool pigeon is a compound word which is a term consisting of two words combined to take on a new, different meaning. The abbreviation of the word stool pigeon is stoolie.
Examples
At this hotel, moving on up, especially for an employee of color, requires one proving oneself to be a reliable stool pigeon in the service elevator. (The Chicago Tribune)
A wannabe-wiseguy who turned government stool pigeon was reduced to tears Thursday when a Post reporter told him his lawsuit against the feds got a thumbs up from a judge. (The New York Post)
It is one thing to be a fall guy and somebody’s stool pigeon; it is a worse thing not to know that that is all you are. (The Jamaica Gleaner)