a member of a 4th-century a.d. church party that maintained that the essence or substance of the Father and the Son is the same (opposed to Heteroousian).
–adjective
2.
of or pertaining to the Homoousians or their doctrine.
Origin: 1555–65; < LGk homooúsi(os) of the same substance (Gk hom(o)- homo-+ ousí(a) substance, essence + -os adj. suffix) + -an
Ho·mo·ou·si·an (hō'mō-ōō'sē-ən, -zē-) n. A Christian supporting the Council of Nicaea's Trinitarian definition of Jesus the Son of God as consubstantial with God the Father.
[Late Latin homoūsiānus, from homoūsius, of same substance, from Greek homoousios : homo-, homo- + ousiā, substance; see Homoiousian.]