What is the term for an apartment building in ancient Rome?

The term for an apartment building in ancient Rome is "insula." This type of structure typically housed the urban population, especially the lower and middle classes. Insulae were often several stories high, and they were constructed to accommodate the growing population in Rome. The design of insulae allowed for a denser living arrangement, where multiple families could reside in one building.

In contrast, the other terms refer to different concepts in Roman society. "Patronus" refers to a patron or protector in the patron-client relationship, where wealthier citizens supported the less fortunate. "Titulus" can denote a title or inscription, often in the context of indicating a property or significant event. "Vicarius" refers to a deputy or substitute, such as an official acting on behalf of a higher authority.

Understanding the specific term "insula" gives insight into Roman urban life and architecture, highlighting how ancient societies organized living spaces in response to their social and economic conditions.