1640s (n.); 1690s (adj.), in reference to followers or doctrines of Faustus Socinus, Latinized name of Fausto Sozzini (1539-1604), Italian anti-trinitarian theologian who held Christ to be human, if divinely endowed, and the Holy Spirit to be divine energy, not a person. He broke with the Church and organized the Polish Brethren.

updated on October 10, 2017

Definitions of Socinian from WordNet

Socinian (n.)
an adherent of the teachings of Socinus; a Christian who rejects the divinity of Christ and the Trinity and original sin; influenced the development of Unitarian theology;
Etymologies are not definitions. From, not affiliated with etymonline.