From Greek 'kategoria' (accusation) — Aristotle transformed it into a term for the most basic classes of being.
A class or division of people or things regarded as having particular shared characteristics; a grouping within a system of classification.
From Late Latin 'catēgoria,' from Greek 'katēgoria' (an accusation, a predication, a category), from 'katēgorein' (to accuse, to assert, to predicate), from 'kata-' (down upon, against) and 'agoreuein' (to speak in the assembly), from 'agora' (assembly, marketplace). The word's journey from 'public accusation' to 'classification' ran through Aristotle, who used 'katēgoriai' as a technical term for the most general classes of being — the fundamental ways something can be described. Key roots: kata- (Greek: "down upon, against
Aristotle's 'Categories' — one of the foundational texts of Western philosophy — identified ten categories of being: substance, quantity, quality, relation, place, time, position, state, action, and passion. These ten ways of classifying reality have influenced every system of classification since, from library catalogues to database schemas. The word went from meaning 'public