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