polycrystalline

The term is a modern scientific compound, directly assembled from classical elements to describe a specific material structure. The prefix "poly-", from ancient Greek, introduces the concept of plurality or multiplicity. It is attached to "crystalline", which itself originates from the Greek krystallos, originally meaning "ice" and later "clear quartz" or "rock crystal", due to its transparent, ice-like appearance. The suffix -ine forms adjectives. Thus, the word's literal construction, "many-crystalled", perfectly captures its technical meaning: a solid aggregate composed of an immense number of microscopic crystalline grains, each with its own lattice orientation, in contrast to a monolithic single crystal.

Structure: poly (many) + crystalline (having a crystal structure) - poly: A combining form from Greek poly-, meaning "much, many". It functions as a prefix denoting multiplicity. - crystalline: An adjective derived from the base word "crystal", from Greek krystallos (ice, clear quartz), plus the English adjectival suffix -ine, meaning "of the nature of, resembling, or made of".