Narc noun – A lawman concerned with narcotics violations. Spy and narc are semantically related. in informer topic. In some cases you can use "Spy" instead a noun "Narc", when it comes to topics like informer to police.
Spy noun – A person who tries secretly to obtain information for one country in the territory of another usually unfriendly country. Narc and spy are semantically related. Sometimes you can use "Narc" instead a noun "Spy". Nearby Word: spying