Party Pooper

Short for "narcotic"

nitrogen narcosis, or getting "narc'd", is the altered state of mind commonly experienced by divers.

NARC (video game), a 1988 arcade game and its 2005 update.

Narc (film), a 2002 film about dirty cops involved in policing the drug trade

National Rainbow Coalition, a Kenyan political party

National Advertising Review Council, a US organization providing self-regulatory services to the American advertising industry

NARC (song), a song on Interpol's album Antics

Narc, an Orc-like character in the parody Bored of the Rings

Narc (narcotics), a term for a narcotics agent (including undercover) or police informant or simply a person who notifies authorities of illicit activity, betraying someone in the process. In the past couple decades it has become a term to mean a tattle tail.

Non-Automatic Relay Center, formerly a station in a military communications network where teletype operators transferred messages using paper tape

National Association of Railway Clubs, an association of sports and social clubs in England, Scotland and Wales

Norfolk Amateur Radio Club, a amateur radio organization in Norfolk County, Ontario, Canada

From Romani nāk = "nose"