Ocean/ˈəʊʃn/ Definition 1 of 2Pro Tip 1/3Locative Nature Ocean usually refers to specific geographic regions, not any body of water. The Nile River flows into the Mediterranean Sea, not an ocean. Pro Tip 2/3Not Just Size Size matters, but oceans are specifically large bodies of saltwater separating continents. Despite its size, the Caspian Sea is not an ocean. Pro Tip 3/3Cultural Symbolism In literature and culture, oceans often symbolize vastness and the unknown. Explorers of old viewed the ocean as the edge of the world.