sectary

1. A sectarian.
2. A dissenter from an established church, especially a Protestant nonconformist.

[Medieval Latin sectārius, from Latin secta, sect. See sect.]

noun

1. One zealously devoted to a religion: devotee, enthusiast, fanatic, votary, zealot. See belief/unbelief, love/hatred, religion.
2. A person who dissents from the doctrine of an established church: dissenter, dissident, heretic, nonconformist, schismatic, sectarian, separationist, separatist. See religion.