pronoun
you (vulgar/archaic); blockhead!
Archaic second-person pronoun, often used with contempt or in a vulgar manner. In modern contexts, it can sound like an insult similar to 'you bastard' or 'blockhead'. Rarely used in everyday speech.
「うぬ、よくも騙したな！」と彼は怒鳴った。
"You bastard, how dare you deceive me!" he shouted.
時代劇では、悪役が「うぬ、覚えておれ」と言うことがある。
In period dramas, villains sometimes say, "You scoundrel, remember this!"
The origin is uncertain. It may be related to the archaic first-person pronoun おの (己), with a shift in usage to second person. The kanji 汝 is a classical Chinese character for 'you', while 己 originally means 'self'.