A term generally used to discribe parts of Florida, most notabley coastal urban centers and Orlando. A large percentage of these areas' residents originate from northern regions, such New York, New England, and parts of southern Canada. As a result, they are almost entirely devoid of things typically associated with the deep south (southern accents, Confederate pride, etc.). Called "South of the South" for it's location south of the Deep South (or Dirty South). Note that in means being physically south of the region called the south, NOT the southern part of the region called the south.
Pretty sure being South of the South is *better* than being in the Deep South, too.