heresy

noun

her·​e·​sy ˈher-ə-sē 

ˈhe-rə-

plural heresies

1

a

: adherence to a religious opinion contrary to church dogma (see dogma sense 2)

They were accused of heresy.

b

: denial of a revealed truth by a baptized member of the Roman Catholic Church

c

: an opinion or doctrine contrary to church dogma

2

a

: dissent or deviation from a dominant theory, opinion, or practice

To disagree with the party leadership was heresy.

b

: an opinion, doctrine, or practice contrary to the truth or to generally accepted beliefs or standards

our democratic heresy which holds that … truth is to be found by majority vote

—M. W. Straight

Synonyms

• dissent
• heterodoxy

Examples of heresy in a Sentence

They were accused of heresy.

He was preaching dangerous heresies.

Recent Examples on the Web

Even rarefied, specialized brands like Ferrari and Rolls-Royce sell sport-utes these days, a concept that would have seemed like heresy in the year 2000. —Will Sabel Courtney, Robb Report, 5 June 2025

Before Francis, anonymous denunciations and heresy trials were painfully common. —Austen Ivereigh, Time, 21 Apr. 2025

Like the trite Black Panther, Sinners is just ethnic heresy. —Armond White, National Review, 18 Apr. 2025

In short, the Catholic Church affirmed that the Jews are part of a living covenant and that antisemitism — including false charges of deicide — are heresy. —Joshua Stanton, New York Daily News, 20 Apr. 2025

Word History

Etymology

Middle English heresie, borrowed from Anglo-French, borrowed (with assimilation to the suffix -ie -y entry 2) from Late Latin haeresis, heresis "school (of philosophy or theology), sect, belief contrary to church dogma," borrowed from Greek haíresis "act of taking, choice, course of action or thought, system of principles, sect, faction," from haireîn "to take, grasp, (middle voice) obtain, choose, prefer" (of obscure origin) + -sis -sis

First Known Use

13th century, in the meaning defined at sense 1a

Kids Definition

heresy

noun

her·​e·​sy ˈher-ə-sē 

plural heresies

1

: religious opinion that is opposed to the doctrines of a church

2

: opinion that is opposed to a generally accepted belief