Someone people call weird because they didn't give the loner a chance to get to know them.
Someone who keeps to themselves, doesn't like conflict, but could kick ass if needed.
Someone that no one really knows except a rare few.
Social when needed and usually very talkative.
A person who's been backstabbed way too many times.
Staying away so no one will get mad or jealous that she smiled and misunderstood it as being "flirting."
Someone who prefers being alone, or with few important people in their life, it's by choice. Less drama.
Small circles, chosen few, anti conflicts, kick ass, less drama.
Someone of these traits could constitute as "loner."