| Noun | 1. | Caspian - a large saltwater lake between Iran and Russia fed by the Volga River; the largest inland body of water in the worldIran, Islamic Republic of Iran, Persia - a theocratic islamic republic in the Middle East in western Asia; Iran was the core of the ancient empire that was known as Persia until 1935; rich in oil; involved in state-sponsored terrorism lake - a body of (usually fresh) water surrounded by land | |