The crossword solution for the term 'FLAT ARRANGEMENT' is LEASE, a five-letter word. A LEASE is a legal agreement between a landlord and tenant that outlines the terms of renting a property. It typically includes information such as the length of the rental period, the amount of rent due, and any other rules or regulations that must be followed. The FLAT ARRANGEMENT refers to the fact that the tenant is renting a FLAT or apartment, rather than a house or other type of property.