Definition of "heresy" in English

noun

1. (religion) A doctrine held by a member of a religion at variance or conflict with established religious beliefs.

   • Heresy meant deliberate departure from the accepted doctrines of the church. It was intellectual and spiritual dissent and concerned the beliefs of Christianity, not the morals of its adherents.

2. (by extension) A controversial or unorthodox opinion held by a member of a group, as in politics, philosophy or science.