Ousia (') is the Ancient Greek noun formed on the feminine present participle of ' (to be); it's analogous to the English participle being, and the Greek ontic. Ousia is often translated (sometimes incorrectly) to Latin as substantia and essentia, and to English as substance and essence; and (loosely) also as (contextually) the Latin word accident — Philosophical Dictionary: Erasmus-Extrinsic which conflicts with the denotation of sumbebekos, given that Aristotle uses sumbebekos in showin… (More on Ousia)