Common GROUND is a term used to describe an area of agreement between two or more parties. In this case, the crossword solution for the term COMMON GROUND is BOSTON, which is a city in Massachusetts, United States. The term 'COMMON GROUND' is often used to refer to a shared understanding between two or more people, and in this case, it could be referring to the city of BOSTON as a place where two or more people can come together and find COMMON GROUND.