nark1 /BrE nɑːk

,
AmE nɑrk
/ I noun
British 1 informal (informant) informatore m, spia f
2 (grumbler) (brontolone m/)(brontolona f)
II transitive verb
British (annoy) scocciare, seccare
III intransitive verb
British 1 (grumble) brontolare (about contro)
2 (inform police) fare la spia, cantare