stoolpigeon

The detective relied on a stoolpigeon to gather evidence against the gang.

侦探依靠一个密探来收集针对那个帮派的证据。

用法提示：名词，指警察的线人或告密者。

Nobody trusts him because they suspect he's a stoolpigeon for the authorities.

没人信任他，因为他们怀疑他是当局的密探。

用法提示：名词，表示被怀疑是告密者的人。

The criminal warned his associate to watch out for any stoolpigeons in the organization.

罪犯警告他的同伙要提防组织里的任何告密者。

用法提示：名词复数形式，泛指组织内的告密者。