Mediterranean Sea, theMed‧i‧ter‧ra‧ne‧an Sea, the /ˌmedətəreɪniən ˈsiː/ (also the Mediterranean)a sea surrounded by the countries of South Europe, North Africa, and southwest Asia. The weather there is hot in the summer, and countries on the Mediterranean coast, such as Greece, Spain, Italy, and southern France, are very popular with British tourists.