A pariah, outcast, or outsider was a person who was rejected by others as being hated, ignored or shunned.
In 2259, Lt. Commander Una Chin-Riley described the Illyrians as outcasts in her log, because their embracing of genetic modification was rejected by the United Federation of Planets. (SNW: "Ghosts of Illyria")
In 2372, Rom was at Quark's Bar, Grill, Gaming House and Holosuite Arcade asking how Quark was, to which his answer was that he was broke, ruined, destitute, and a pariah. (DS9: "Body Parts")