nark

 Longman Dictionary of Contemporary English 5++朗文当代英语 5++LDOCE 5++朗文 5++

Related topics: Crime, Police

nark /nɑːk $ nɑːrk/ noun [countable] informal especially British English  SCCSCPsomeone who is friendly with criminals and who secretly tells the police about their activities 〔向警方提供情报的〕线人，密探，卧底 SYN informer

Examples from the Corpus

nark• I know if he is a thief, right, a beggar, a pimp, a copper's nark.

nark nounChinese  

criminals who is with and friendly someone Corpus who

nark
nark /nɑːk $ nɑːrk/ noun [countable] informal especially British English
someone who is friendly with criminals and who secretly tells the police about their activities
   SYN  informer

narkBrE /nɑːk/ 🔊NAmE /nɑːrk/ 🔊 noun (BrE, slang) a person who is friendly with criminals and who gives the police information about them 警察的线人