What is the term for those eligible to be elected to the town council?

The term that refers to those eligible to be elected to the town council is "Ordo decurionum." This group was specifically composed of individuals who held the status to serve as decuriones, the municipal councilors in Roman towns. These councilors played a crucial role in local governance, managing various aspects of civic life, including financial matters and public works.

In Roman society, the Ordo decurionum comprised local elites, often landowners or individuals of significant wealth and social standing, who were responsible for making decisions that affected the community. This system was fundamental in Roman municipal administration and allowed for a level of local self-governance under the broader framework of the Empire.

The other terms refer to different groups within the Roman social structure. For example, the Ordo senatorum refers to the Senate, the body of elected officials governing broader Roman territory, the Ordo equitum pertains to the equestrian order or knights, a social class of wealthy citizens who were not part of the Senate, and the Ordo plebis relates to the common people or the lower classes in Roman society. Thus, "Ordo decurionum" distinctly applies to those who held the right to be elected to the town council.