A Birkett
A Birkett is a person who acts like they have a brain disorder. It's either real or they're just being mean. They call people idiots, and sometimes they're right.
He called me a Birkett. I guess I'm an idiot.
She's a Birkett. She thinks she's smart, but she's not.
He's a Birkett. He said I was an idiot. I was.