The term "overseer of slaves" refers to a person who was responsible for overseeing the work and managing the affairs of slaves. However, due to the negative connotations associated with the term "overseer," there are several synonyms that can be used instead. One such synonym is "slave driver," which is a person who is in charge of overseeing the forced labor of slaves. Other synonyms include "slave master," "slaveowner," or "slaveholder." These terms emphasize the ownership and control of slaves, which is why they are often used to refer to individuals who were involved in the brutal practice of slavery.