The term 'Great Expanse' can be defined by the crossword solutions of 'VASTNESS' (8 letters), 'OCEAN' (5 letters) and 'SEA' (3 letters). It is a phrase that is often used to describe a large area of land or water, usually with a vast amount of space between its boundaries. The term is often used to refer to the OCEAN, which is the largest body of water on Earth, covering over 70% of the planet's surface. It is also used to describe large areas of land, such as deserts, forests, and plains. In either case, the term 'Great Expanse' implies a large area of land or water with a great deal of space between its boundaries.