Southland noun4 •The American South: a geographic region consisting of the Upper South and Deep South of the United States.Too long has our beloved Southland been bogged down in a tragic effort to live in monologue [...] — 1963 •A region in the far south of the South Island of New Zealand, which includes Fiordland and Stewart Island. •A territorial authority which includes the majority of Southland region; in full, Southland District. •Southern California: a geographic region constituting the portion of California approximately south of the Bay Area.