nark 1
/nahrk/ , n.
1. Brit. Slang. a stool pigeon or informer.
2. Chiefly Australian Slang. an annoying person.
v.i.
3. Brit. Slang. to act as a police informer or stool pigeon.
4. Chiefly Australian Slang. to become annoyed.
[ 1860-65; nak nose ]
nark 2
/nahrk/ , n.
narc.