Heretical means going against what the faithful are supposed to believe. A heretical view, heretical opinions, frankly heretical.
The religious sense was once a capital matter, and the word still carries that weight. It is now used lightly of any opinion an established group will not hear, which is a joke about how they behave.
1adjectivehereticalGoing against what the faithful are supposed to believe.
“In the Middle Ages, saying that the Earth moved around the Sun was seen as heretical.”
heretical is a quality.
Greek hairetikos means able to choose, from hairesis, a choosing, which came to mean a sect.
Medieval Latin
haereticālis
Middle French
eretical
English, today
heretical
From Middle English -, Middle French eretical and from Medieval Latin haereticālis, from haereticus, equivalent to heretic + -al. See heretic.
Etymology from Wiktionary, CC BY-SA