Smoothbrain 

A way of calling somebody very stupid that requires them to be smart, in order to understand.

Person 1: Dude, why did you think that was possible? You're such a smoothbrain.
Person 2: ...huh? What the hell is that supposed to mean
Laughtrack: *laughs*

Smoothbrain by Glitchgoat September 5, 2019

Smoothbrain 

Smoothing out your brain will also negatively affect your intelligence and reason, this is precisely why smooth-brainers are often called "stupid hippies" or "vegans" by lower class citizens because they seem to become increasingly stupid as they level up. This will however all pay off in the end, when you reach the ultimate goal of unity with the universe. The path to godlike status is and literally goes through the "rough", which is also why around half of the worlds population decide to stay in this lower level of "rough" class brainers, which usually leads to a steady decline of their life into a criminal and abuse filled life-path, which always tends to end in horrible death.

Look at that idiot he must have a smoothbrain

Smoothbrain by Smoothbrainer69 October 22, 2020

Smooth Brain 

A stupid person; it refers to the lack of surface area on an individual's brain. The general thought is that the more surface area (wrinkles, creases, etc.) a brain has, the smarter the person is. Conversely, a person with a smooth brain (no wrinkles) has less surface area and would therefore be stupid.

That fucking smooth brain put his shirt on backwards again...

That smooth brain is dumber than a pile of shit.

Smooth Brain by Tip Tank June 8, 2011

Smooth brain 

A cute brain

J: O, you have a smooth brain
O: Does this mean I have a cute brain?
*L, M, N, O, and P all start laughing*

Smooth brain by Ace the simp May 5, 2023

Smooth Brain 

Opposite of big brain. Smooth brain refers to an idiot or someone dumb. Neuroscientists believe the more folds you have in your brain means the smarter you are. Therefore if you are called smooth brain, you have less folds and therefore dumb.

How did you forget to lock the door? Good move, smooth brain.

You don’t know basic math? Smooth brain 🙄

Smooth Brain by TheoPham September 13, 2019

Smooth Brain 

adj. word to describe people that are slow or stupid

adj. describes unfunny, uncool people that are lame

“Oh look at Marquis, he’s so smooth brained”

Smooth Brain by dirtydikdan October 19, 2021

Smooth-brain 

A derogatory term used to describe someone after they have done something unintelligent, clumsy, or foolish. This term implies a below average intelligence due to an abnormally shaped brain. The expression is used almost exclusively for criticism.

Dude 1: Hey, did you hear that Mike literally got in an accident with a parked car yesterday!
Dude 2: Ya, I cant believe it. What an absolute smooth-brain.

Smooth-brain by Mike N. Ike April 3, 2019