invisible chair 

A person everyone in class, who's existence is ignored. They are usually the last person to be picked into groups (often the teacher choses groups for them). They may be gone for days without being noticed, often sit in the lunch table by themselves and sit in the corner of the class. They are often the most nice people with the most interesting stories to share and its a shame they are often ignored. Invisible chairs are not losers, they just enjoy the company of themselves.

Teacher: Class, Mel doesn't have a group
Class: Who's Mel?
Mel: I'm just an invisible chair

invisible chair by LoreaFendiDiamond May 17, 2014

Invisible chair 

When a person, usually a female, puts their bodies in a position to where it almost looks like they are sitting on a chair and takes a picture. But, it is an invisible chair because no chair is actually present.

synonym: poppin it out

"Ew did you see Shellys pic she put on sc? There's nothing!!!"
"I know, she's just sitting on an invisible chair"

Invisible chair by daka daka bill$ July 27, 2016