The noun heresy means an action or a belief that most people think is wrong, because it is against the official or popular opinion. It also means a belief that is seriously against the principles of a particular religion.

Synonyms are blasphemy, fallacy, apostasy, or atheism.

The word origins from Old French (12th century) heresieeresie meaning “heresy” and by extension “sodomy, immorality” (source also from Latin hæresis meaning “school of thought, philosophical sect”. The Latin word is from Greek hairesis meaning “a taking or choosing for oneself, a choice, a means of taking, a deliberate plan, purpose, philosophical sect, school”, from haireisthai meaning “take, seize” middle voice of hairein meaning “to choose”.

The people convicted him for spreading a heresy against the current government.

It is never right to torture people who are charged as advocating a heresy against any particular church.

He denounced the traitor who intended to create discord by spreading the heresy.