An opinion held in opposition to the established or commonly received doctrine, and tending to promote a division or party, as in politics, literature, philosophy, etc.; -- usually, but not necessarily, said in reproach.
- An opinion or a doctrine at variance with established religious beliefs, especially dissension from or denial of Roman Catholic dogma by a professed believer or baptized church member.
- Adherence to such dissenting opinion or doctrine.
- A controversial or unorthodox opinion or doctrine, as in politics, philosophy, or science.
- Adherence to such controversial or unorthodox opinion.