noun / verb

nark

NARK/nɑːrk/

Someone who reports others to authorities, or the act of doing so.

The nark discreetly shows the police officer evidence of a forced-open storage unit.

A young adult informer discreetly reports suspected illegal activity to an older police officer, showing him a text-free phone photograph of a cut padlock and a forced-open storage-unit door.

Etymology

Nark probably comes from Romany nak, ‘nose,’ though the supplied account does not explain how this became ‘informer.’ Its meaning and spelling later tended to merge with narc, a shortening of ‘narcotics agent.’

More examples

She refuses to nark on her friends to the police.
They called him a nark after he reported the theft.
He narked on his coworkers for stealing from the warehouse.

Forms

nark · narks · narked · narking

Similar words

informer: Less slangy; specifically someone who supplies information to authorities.
snitch: Similarly informal, often used for reporting minor rule breaking.
inform: A more neutral verb that also covers simply giving information.