- a member of any of several European churches professing to be truly Catholic but rejecting certain modern Roman Catholic doctrines, dogmas, and practices, especially the dogma of papal infallibility.
- a member of any of several minor churches, especially in the U.S., differing from the Roman Catholic Church chiefly in their rejection of the ecclesiastical authority of the Roman Catholic hierarchy.
- of or relating to several small national Churches which have broken away from the Roman Catholic Church on matters of doctrine
- a member of one of these Churches
