- a pigeon or other bird used as a decoy
- a person serving as a decoy
- Informal a spy or informer, esp. for the police
See stool pigeon in American Heritage Dictionary 4
- Slang A person acting as a decoy or as an informer, especially one who is a spy for the police.
- A pigeon used as a decoy.
Origin: From the practice of tying decoy pigeons to a stool to attract other pigeons
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