Homoousion

Homoousion (/ˌhɒmoʊˈuːsiən/ HOM-oh-OO-see-ən; Greek: ὁμοούσιος, translit. homooúsios, lit. 'one in being', from ὁμός, homós, "same" and οὐσία, ousía, "being") is a Christian theological doctrine pertaining to the Trinitarian understanding of God. The Nicene Creed describes Jesus as being ὁμοούσιος, "one in being" or "of single essence", with God the Father. It is one of the cornerstones of theology in Nicene Christianity.

The term was adopted at the First Council of Nicaea to clarify the ontology of Christ. In Latin, which is lacking a present participle of the , the translation consubstantialis is used (substantia being the traditional Latin translation of the Aristotelian term ousia).