- the region of the world that lies in the Southern Hemisphere of the Atlantic Ocean, including all the coastal countries, islands, and archipelagos located there: I’ve got relatives throughout the South Atlantic, but my cousins in Uruguay are the only ones I really know.
- of or relating to the region of the world that lies in the Southern Hemisphere of the Atlantic Ocean, often specifically to the South Atlantic Ocean itself: their South Atlantic adventures aboard a small fishing boat.
