koostus

Koostus is an Estonian noun meaning the way in which parts are combined to form a whole; the makeup, arrangement, or composition of something. It denotes the internal structure, components, and relationships within a system, object, or work, as opposed to the individual elements themselves. The term is derived from the Estonian verb koostama (to compose or assemble) with the noun suffix -us.

Koostus is used across disciplines to describe how something is put together. In science and engineering, it refers to the overall composition of a material—the elements present and their proportions. In nutrition labeling, it describes the makeup of a food product, including ingredients and their relative amounts. In the arts, koustus can denote the arrangement of visual elements in a design or the structure of a musical or literary work. In linguistics and rhetoric, it can describe how words and ideas are organized to form a coherent text.

Careful use of the term helps distinguish between the "composition" (the overall makeup) and "constituents" or "components" (the individual parts). Related Estonian terms include koostis (the constituents or composition) and koostama (to compose).