What is the term for the act of excluding someone from society by general consent?

The term that describes the act of excluding someone from society by general consent is "ostracism." This concept comes from ancient Greece, where it referred to a practice in which a person could be exiled from the city-state for a period, typically around ten years, through a vote by the citizens. The key elements of ostracism involve a collective decision not to accept an individual within a community, reflecting a social sanction that aims to protect the group or express disapproval of the person's actions or character.

The other choices do not convey the meaning of exclusion. "Sporadic" refers to something occurring occasionally or in irregular intervals, lacking the continuity or consensus that characterizes ostracism. "Perennial" signifies something that is enduring or constantly recurring, which does not relate to the concept of societal exclusion. "Mitigate" means to lessen or reduce the severity of something, typically in a negative context, such as pain or damage, rather than referring to social dynamics or exclusion.