The term "greater city" refers to a larger urban area that encompasses several cities or towns. Some synonyms that can be used for "greater city" include "metropolis," "megalopolis," "urban agglomeration," "conurbation," and "city region."
A metropolis is a large and important city that serves as the center of economic and cultural activity. Megalopolis, on the other hand, refers to a group of cities or urban areas that have grown together to form a single densely populated region.
Urban agglomeration is a collection of urban areas that have grown together to form a larger urban entity. Conurbation is similar to urban agglomeration, but it commonly refers to a group of urban areas that are fused together due to their proximity.
Lastly, a city region refers to an urban area that consists of a central city and its surrounding suburbs, towns, and rural areas.