Ousia (; ) is analogous to the English participle being and the adjectival ontic used in contemporary philosophy. 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 (sumbebekós).

Ousia (; ) is analogous to the English participle being and the adjectival ontic used in contemporary philosophy. 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 (sumbebekós).