The place where you sit for 99% of your Childhood. An alternative to Sandpaper. The smooth side is on the back the rough side is where your ass goes. The backs are shaped like a fucking U which will ruib your back for years to come.
Teacher: Why have you taken your blazer off?
Stundent: Because my ass hurts from these fucking School Chairs so I have to cover it.
A really really really inappropriate euphemism.
"Oh man, I did the school chair last night, it was so tight, dawg!"
"Mmm man, she got the school chair like nobody's business."
"You got any of that young school chair?"