Funteen
A person, generally between the ages of 18 and 20, who has begun college but still has the mentality of a high schooler. They generally don't recognize the amount of responsibility that they have, and still find joy in everything. Some may also may be life wreckers because of their lack of regard for anyone but themselves.
Man 1: Have you met Jessica?
Man 2: Yeah she's a total funteen.
Man 1: I love funteens.
Man 2: Yeah she's a total funteen.
Man 1: I love funteens.