A name applied to the beliefs of those eastern Christians who in the 4th century were not altogether satisfied with the formula "consubstantial" of the Nicene Council.
This party was divided into many factions; of these the nearest to orthodoxy was that led by Basil of Ancyra.
For half a century they caused considerable confusion in the Eastern Church.
In their explanation of the Trinity they inclined to the view of subordinating the Son to the Father, not always realizing that any real subordination militated against the divinity of the Second Person.
Much of the bitterness of the controversy was caused by a personal hostility towards Athanasius for his determined stand against Arius at Nicea.
The temporary success of the semi-Arians was largely due to their favor at court; when this favor was withdrawn the influence of the party began to wane and after the Second General Council (Constantinople, 381) rapidly disappeared.
New Catholic Dictionary