Polytypes

Part of speech: noun

Definitions

1. A classification of types that differ in form or structure while retaining a common base identity
2. Referring to the various forms of a chemical compound or biological species that exhibit different physical characteristics
3. Describing the distinct manifestations or variations of a single underlying system or structure

Etymology: "Polytypes" is the plural of "polytype," a noun built from two parts: "poly-," from Ancient Greek "polús," meaning "many" or "much," and "type," from Greek "túpos," meaning "impression" or "mark struck by a blow." Together they describe something that has many forms or types. The Greek prefix "poly-" appears in many scientific coinages, such as "polymer" and "polygon," and it does the same job here: a single chemical compound or biological species that occurs in several distinct structural forms, each with its own physical characteristics. The "type" element carries the same classical sense it has in words like "stereotype" and "archetype."