outcast:

(plural: ‘outcasts‘; pronunciation: the letter ‘c’ is said with a ‘k’ sound as in “king” — for the right pronunciation of this word, please click here)

a social outcast

a person who is (rejected by) sent away  from a group of friends, an association or a social system and is never allowed to join again, probably because of some disagreement, difference of opinion, etc.;

a castaway;

e.g.

All the outcasts from the society gathered together and formed themselves into a band of outlaws!

Robert has been made an outcast by his family because he has married a woman of low social status.