A person who is unable to realize their own mistakes, and tend to usepower whenever he/she it can to make up for crippling low self-esteem that is obvious to everyone.
Also uses tremendous big words to seem smarter and older than he/she really is.
Belonging to a low social class, or typical of people who belong to a low social class.
A certain individual showing traits of little common sense whatsoever. Usually referenced in a video game to show a player of little skill due to his/her little knowledge of the game itself.
Mom (to Dad): "(Insert name) can't play (Insert game) to save his life!"
Dad: "I know. I'm sure you already know, but he's such a plebby."