Homoousians , (Gr. the same, and being, essence), in ecclesiastical history, a term which was originated in the 4th century to distinguish the Athanasian or orthodox party from the Arians, who were called, among other names, Heterousiasts different, and and the Semi-Arians, who were termed Homoiousians (Gr. similar, and

The Homoousians maintained that the Son was of the same essence as the Father; the strict Arians, that he was of different essence; and the Semi-Arians, that he was similar to the Father in essence, but not identical with him. (See Arianism.)