stoolpigeon
Longman Dictionary of Contemporary English 5++LDOCE 5++stool·pi·geon /ˈstuːlˌpɪdʒɪn/ noun [countable] American English informal SCCTELLsomeone, especially a criminal, who helps the police to catch another criminal, usually by giving them information 〔警察的〕线人，内线，告密者 SYN informerOrigin stoolpigeon (1800-1900) stoolpigeon “pigeon tied to a wooden frame to attract other birds for shooting at” ((1800-1900))
stool·pi·geon nounChineseSyllable
stoolpigeon
stool‧pi‧geon /ˈstuːlˌpɪdʒən, ˈstuːlˌpɪdʒɪn/
noun [countable] American English informal
SYN informer
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 Origin: stoolpigeon 'pigeon tied to a wooden frame to attract other birds for shooting at' (1800-1900)
SYN informer