Smooth brainer 

A slang used to call someone dumb, stupid, of low IQ, etc.

Origin: As the amounts of folds on the cerebrum of a mammal brain determines the intelligence of the being, having no folds would mean that they have on intelligence.

Ignore them, they're just some smooth brainers

Smooth brainer by RAPHlEL March 15, 2023

smooth-brained 

An insult referring to the absence of wrinkles present in the human telencephalon(cerebrum) -- the largest region of the mammalian brain. Literally implying idiocy at a physiological level.

Those smooth-brained idiots voted for G.W. Bush twice!

smooth-brained by drastic_quench May 23, 2008

smooth brained 

Your brain doesn't work right and the gears don't function right. Otherwise said as you are stupid, dumb, an idiot.

Hey Darrell those eggs go in the fridge you smooth brained mother fucker.

smooth brained by Smooth brained mf October 3, 2019

Smooth brained crayon eating ape 

Retail investors who invested in GameStop. They demanded a change from the SEC to ban PFOF(Payment for order flow) which was invented by Bernie Madoff and used by Citadel and company to manipulate markets. drsgme.org

Smooth brained crayon eating apes are making DD's on r/Superstonk.

Smooth brained crayon eating ape by fellowApe June 11, 2022

Smooth-Brained 

A person who could be very well-informed and high-functioning, possibly even quite intelligent in certain areas, but is an idiot nevertheless. Usually a smooth-brained person has never thoroughly examined their beliefs, is generally susceptible to ideology, and has enjoyed a relatively comfortable life free of struggle or adversity.

Smooth-brained can also describe an article, film, or any other piece of content that presents a view of the world that betrays the author's complete alienation from any of the material conditions that define most peoples' lives.

Can also be used as a noun, for example: smooth-brain.

Did you read the latest smooth-brained think piece about rising division in America?
Nah, I can't even read that both-sides bullshit.

Smooth-Brained by SBCP October 9, 2021

Smooth brained Robbie

A smooth brained robbie is an individual who is unaware of modern slang. They can try but they still won't grasp the current slang, truly they will never be hip with the teens. If you encounter a "smooth brained Robbie" do not hesitate to laugh at their incompetence, because it is funny.

Jeff: "that was awesome, no cap"
Robbie: "why aren't you wearing a hat? Its cold outside."
Jeff: "oh you poor smooth brained robbie".

Smooth brained Robbie by Soggyfroggy February 22, 2022

Smoothbrained Skelder 

An Among Us player who always plays on the Skeld map no matter what. They are often noobs or people who leave when they aren't imposters. You will usually find them in games with only one imposter and a maximum of ten players instead of the new 15-player servers.

People who play on the Skeld are fine, but if they're a Smoothbrained Skelder then it's annoying.

Smoothbrained Skelder by some guy who uses the Internet October 7, 2021