What is the meaning of the prefix poly?

The meaning of the prefix poly is “many.”

Poly- comes from the Ancient Greek word polys, meaning “many” or “much.” It entered English through scientific, academic, and technical vocabulary, where it usually indicates that something contains or relates to multiple parts, kinds, or units. For example, a polyglot knows many languages, a polygon has many sides, and a polymer is made from many repeating molecular units.

Poly- is related to, but not identical with, prefixes such as mono- (“one”), bi- or di- (“two”), and multi- (“many” or “more than one”). It also should not automatically be confused with pan-, which generally means “all” or “across an entire group.” Thus, “many” is the standard concise answer for a vocabulary or trivia question about poly-.

The prefix appears in words from several fields: polytheism involves belief in many gods, polysaccharides contain many linked sugar units, and polyatomic describes an ion or molecule made of multiple atoms. In ordinary English, poly- can sometimes suggest “much” as well as “many,” but “many” is the canonical dictionary-style translation.