Firm Understanding can be defined as a clear and comprehensive comprehension of a concept or situation. It is often used to describe a strong GRASP of a particular subject or idea. The term can also be used to describe a mutual agreement between two parties, such as a business contract. In this context, Firm Understanding implies that both parties have a thorough understanding of the terms and conditions of the agreement. The crossword solution for Firm Understanding is GRASP, which is a verb meaning to take hold of something firmly.