The phrase "more built-up" refers to an area that has been developed with buildings and infrastructure. There are several synonyms that can be used to describe such an area, including urbanized, densely populated, highly developed, industrialized, and metropolitan. These words all imply a level of development and progress, and they are often used to describe cities and towns with a large population and extensive infrastructure. Additionally, these words can be used to describe areas that are experiencing rapid growth and development, such as emerging markets or newly industrialized countries. Whatever the context, the phrase "more built-up" and its synonyms suggest a bustling, dynamic environment full of opportunity and activity.