stool‧pi‧geon /ˈstuːlˌpɪdʒən, ˈstuːlˌpɪdʒɪn/
noun [countable] American English informal[
Date: 1800-1900;
Origin: stoolpigeon 'pigeon tied to a wooden frame to attract other birds for shooting at' (1800-1900)]
someone, especially a criminal, who helps the police to catch another criminal, usually by giving them information
Synonym : informer [TahlilGaran] Dictionary of Contemporary English ▲