nacademic
A know-it-all who acts like they're the smartest person in the room, but they're just full of garbage.
My cousin is a nacademic. He says he's a physics master, but he can't explain why the sky is blue.
She told me she's a chemistry whiz, but she can't even mix two colors without messing it up.
He says he's a literature genius, but he can't name a single book.