A social stigma is a mark of disgrace imposed on an individual by other individuals or a social group. In popular usage it often refers to any negative sanction or to disapproval for nonconformity.
An undesirable differentness of an individual that disqualifies him or her from full social acceptance. It is an attribute or stereotype that departs negatively from the expectations of others.
Different patterns of coercion and exclusion have been exercised over time against socially stigmatized groups, notably those thereby defined as mad.