[syn: annoy, rag, get to, bother, get at, irritate, rile, nark, nettle, gravel, vex, chafe, devil]
2.  inform or spy (for the police); 
The Collaborative International Dictionary of English v.0.48:
nark \nark\ n. [from narcotics.]
   A law enforcement agent specializing in narcotics law
   violations. [slang]
   [PJC]
WordNet (r) 3.0 (2006):
nark
    n 1: an informer or spy working for the police [syn: nark,
         copper's nark]
    2: a lawman concerned with narcotics violations [syn: narc,
       nark, narcotics agent]
    v 1: cause annoyance in; disturb, especially by minor
         irritations; "Mosquitoes buzzing in my ear really bothers
         me"; "It irritates me that she never closes the door after
         she leaves" [syn: annoy, rag, get to, bother, get
         at, irritate, rile, nark, nettle, gravel, vex,
         chafe, devil]
    2: inform or spy (for the police)