The village idiot in strict terms is a person locally known for ignorance or stupidity, but is also a common term for a stereotypically silly or nonsensical person. The term is also used as a stereotype

Stereotype

A stereotype is a popular belief about specific social groups or types of individuals. The concepts of "stereotype" and "prejudice" are often confused with many other different meanings...

 of the mentally disabled. It has also been applied as an epithet

Epithet

An epithet or byname is a descriptive term accompanying or occurring in place of a name and having entered common usage. It has various shades of meaning when applied to seemingly real or fictitious people, divinities, objects, and binomial nomenclature. It is also a descriptive title...

 for an unrealistically optimistic or naive individual.

The village idiot was long considered an acceptable social role, a unique individual who was dependent yet contributed to the social fabric of his community. As early as Byzantine

Byzantine

Byzantine usually refers to the Roman Empire during the Middle Ages.Byzantine may also refer to:* A citizen of the Byzantine Empire, or native Greek during the Middle Ages...

 times, the "village idiot" was treated as an acceptable form of deranged individual that fulfilled the conception of normative social order. The concept of a "village savant" or "village genius" is closely related, often tied to to the concept of Pre-Industrial Anti-intellectualism

Anti-intellectualism

Anti-intellectualism is hostility towards and mistrust of intellect, intellectuals, and intellectual pursuits, usually expressed as the derision of education, philosophy, literature, art, and science, as impractical and contemptible...

, as both figures are subjects of both pity and derision.