Commoners in Ancient Rome were called what

Masses, or Common people.

Explanation:

There were a couple of names but these were most common. Especially during the Roman times of social class isolation.

Ex;

Higher Class (Kings / Wealthy) > Middle Class (Steady, some rich) > Lower Class (Poor) > Slaves (Broke and owned by higher classes, and some middle)

Plebeians

Explanation:

In Europe, a distinct concept analogous to common people arose in the Classical civilization of ancient Rome around the 6th century BC, with the social division into patricians (nobles) and plebeians (commoners).