The term 'incorporate into a city' can be summarized by the crossword solution 'ANNEX, ' which is a five-letter word. Annexation is the process of adding land to a city, town, or other municipality. It is usually done through a legal process that involves the passing of a law or ordinance by the governing body of the municipality. This process is often used to expand the boundaries of a city or town, and can also be used to incorporate unincorporated areas into a city or town.