A person who does not fit in anywhere, does not enjoy being alone, and is forced to because of it. They tend to be Jacks/Jills-of-all-trades and get bullied a lot. In addition, they tend to be popular because people see things in the lost loner that he/she doesn't.
P1: That lost loner looks kind of sad...
P2: I know! maybe we should bully him.
Lost loner: Fuck off. If you aren't going to be nice, fuck off and go be an idiot like the rest of this shitty planet.