Canary noun – Someone acting as an informer or decoy for the police. Stoolpigeon is a synonym for canary. In some cases you can use "Stoolpigeon" instead a noun "Canary".
Stoolpigeon noun – Someone acting as an informer or decoy for the police. Canary is a synonym for stoolpigeon. You can use "Canary" instead a noun "Stoolpigeon".