Boys (and girls) who, rather than finding their own individuality, choose to conform to particular patterns of dress, music and behaviour. Typical indicators: medium-long hair elaborately cut to fall over the face; tight, possibly torn jeans; and a vapid and self-involved personality that makes them insufferable to be around.
Person A: Hey, check out those emo boys!
Person B: Man they're cool. I read on Wikipedia that you can't have emotions unless you have EXACTLY that hair cut.
Person A: Word.