in ecclesiastical history, the name of a fanatical sect which sprang up in the Greek and Eastern churches towards the close of the 12th century: the fanatics of this denomination professed to believe in a double Trinity, rejected wedlock, abstained from flesh, treated with the utmost contempt the sacraments of Baptism and the Lord's Supper, and all the various branches of external worship; placed the essence of religion in internal prayer alone, and maintained, as it is said, that no evil being, or genius, dwelt in the breast of every mortal, and could be expelled from thence by no other method than by perpetual supplication to the Supreme Being. The founder of this enthusiastic sect is said to have been a person called Leucopetrus, and his chief disciple Tycheius, who corrupted, by fanatical interpretations, several books of scripture, and particularly St Matthew's gospel.