nonconformist

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. One who does not conform to, or refuses to be bound by, accepted beliefs, customs, or practices.
2. n. A member of a Protestant church not observing the doctrines, usage, or polity of a national or established church, especially the Church of England.

Century Dictionary and Cyclopedia

1. n. One who does not conform to some law or usage, especially to some ecclesiastical law.
2. n. Specifically, in English history, one of those clergymen who refused to subscribe the Act of Uniformity passed in 1662, demanding “assent and consent” to everything contained in the Book of Common Prayer, and by extension any one who refuses to conform to the order and liturgy of the Church of England. See dissenter, 2.
3. n. In entomology, the noctuid moth Xylina zinckeni: an English collectors' name, applied in distinction from X. Conformis. Synonyms Dissenter, etc. See heretic.

Wiktionary

1. n. Someone who does not conform to accepted beliefs, customs or practices.
2. adj. Not conforming to established customs etc.

GNU Webster's 1913

1. n. One who does not conform to an established church; especially, one who does not conform to the established church of England; a dissenter.

WordNet 3.0

1. adj. not conforming to some norm or socially approved pattern of behavior or thought
2. n. someone who refuses to conform to established standards of conduct
3. n. a Protestant in England who is not a member of the Church of England
4. adj. not conforming to established customs or doctrines especially in religion