The term 'Agreement Union' can be broken down into four crossword solutions: PACT (4 letters), AMEN (4 letters), NAFTA (5 letters), and LEASE (5 letters). A PACT is a formal agreement between two or more parties, usually written and legally binding. AMEN is a Hebrew word meaning 'so be it' that is often used to express agreement or acceptance. NAFTA stands for the North American Free Trade Agreement, which was signed in 1994 by Canada, Mexico, and the United States to reduce trade barriers between the three countries. Finally, a LEASE is a contract between a landlord and tenant that outlines the terms of renting a property.