1) N-PROPER: the N The Mediterranean is the sea between southern Europe and North Africa.
2) N-PROPER: the N The Mediterranean refers to the southern part of Europe, which is next to the Mediterranean Sea.

Barcelona has become one of the most dynamic and prosperous cities in the Mediterranean.

3) ADJ Something that is Mediterranean is characteristic of or belongs to the people or region around the Mediterranean Sea.

There was very little meat in the classic Mediterranean diet.

English dictionary. 2008.