Learnert

Someone who is learning something but they have already learned it

"Hey, isn't this his second time in this class?
Yeah, he's a learnert"

Twacher

An adjective to describe a teacher who is annoying.

Person 1 "do you have Mrs. Thotiana?"
Person 2 "yeah I had her last year, she's such a twacher."
Person 1 "Yeah, fuck that bitch."