Other forms: polyhistors
A polyhistor is a person whose knowledge spans a vast range of subjects. You probably know someone who seems to know everything about just about everything: You might call that person a polyhistor.
The word polyhistor comes from the Greek poly, meaning "many," and histōr, meaning "learned" or "knowing." Historically, the polyhistors were scholars of the 16th and 17th centuries who attempted to catalog all known human knowledge. A polyhistor is very similar to a polymath, a person skilled in many different practical areas (e.g., Leonardo da Vinci, skilled as an artist, scientist, architect, engineer, etc.). But a polyhistor is more associated with vast, encyclopedic knowledge and learning.