Nark/Narked

British slang from the late 19th century for a police informer as in ‘a copper’s nark’. The OED gives its origin as the Romany word, nak, meaning nose, a good nose being an important requisite for a nark. See also Grass. Narked is also British slang from the late 19th century for annoyed or irritated, and is supposedly linked to the Romany origin from people sticking their noses into business that does not concern them and thus causing annoyance.