Nouns

(n)nark, copper's narkan informer or spy working for the police
(n)narc, nark, narcotics agenta lawman concerned with narcotics violations

Verbs

(v)annoy, rag, get to, bother, get at, irritate, rile, nark, nettle, gravel, vex, chafe, devilcause 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”
(v)narkinform or spy (for the police)