Living together in communities. Of or relating to communal living. Of or relating to human society and its modes of organization: social classes; social problems; a social issue. Living together in organized groups or similar close aggregates: Ants are social insects. Involving allies or members of a confederacy. Of or relating to the upper classes. Inclined to seek out or enjoy the company of others; sociable. Spent in or marked by friendly relations or companionship. Intended for convivial activities. Of, relating to, or occupied with matters affecting human welfare: social programs. An informal social gathering, as of the members of a church congregation.