Built-up is a term used to describe an area that has been developed over time. Accreted means to grow or increase gradually, and is often used to describe the growth of a population in an area. Urbanized means to make an area more like a city, with buildings and infrastructure. Erected means to build something, such as a building or structure. AMASSED means to gather or accumulate something, such as resources or wealth. Crescendoed means to gradually increase in intensity or volume. URBAN means relating to a city or town. Accrued means to accumulate over time. Together, these words describe the process of an area gradually becoming more populated and developed over time.