(1) A class name for a number of early sects which revived Gnostic and Manichean principles and worshiped the devil, in some instances cursing God while they did so.
They are also known as Luciferites, e.g., the Stedingers in northern Germany (13th century); also a similar group of sectarians in Austria (14th century).
(2) The adherents of the schismatical bishop, Lucifer of Cagliari, in Sardinia (died 370 or 371) who dealt very harshly with converts from Arianism.
He apparently was not reconciled with the Church before his death.
New Catholic Dictionary