obscurant
A smelly, brainy know-it-all who hides facts like they’re dirty socks, just so you can’t understand anything they say.
My history teacher is an obscurant, he talks about ancient wars like they’re personal beefs.
My cousin is an obscurant, he hides all the answers so he can look smart.
My uncle is an obscurant, he hides his own money so he can pretend he’s rich.