Brainuloid
When someone is acting realllllllllllllllllllllllllllllllly stupid, but they're also smart sometimes but they are just being annoying. basically a synonym for stupid.
Oh my god man Johnathon is being such a brainuloid!
Dude stop, you're being a brainuloid right now.
Dude stop, you're being a brainuloid right now.