narc
/nɑːk
/(also nark)
noun informal, chiefly North American
An official narcotics agent.Lab busts have soared since last fall when Wright, a former narc, took over the county's 13-man drug task force....
- Les knew enough to be cautious, he sure as hell didn't want to wind up talking to a narc. or an undercover cop.
- It would take a mind working on a very different level to consider the sentence being for four sales of pot to an undercover narc at an area high school.
Origin
1960s: abbreviation of narcotic.