adj of or pertaining to pelagius, or to his doctrines.
2. pelagian ·adj of or pertaining to the sea; marine; pelagic; as, pelagian shells.
3. pelagian ·noun a follower of pelagius, a british monk, born in the later part of the 4th century, who denied the doctrines of hereditary sin, of the connection between sin and death, and of conversion through grace.