Salty Expanses is a term used to describe large bodies of water that have a high salt content. The term is often used to refer to the seas, which are four-letter words that can be used to complete the crossword solution. Seas are large bodies of water that are connected to the ocean and are usually salty due to the evaporation of water from the surface. They are home to a variety of marine life and are important for transportation, recreation, and commerce.