conspiracy theory

noun

plural conspiracy theories
: a theory that explains an event or set of circumstances as the result of a secret plot by usually powerful conspirators
the conspiracy theories surrounding Kennedy's assassination
also : a theory asserting that a secret of great importance is being kept from the public
… is best known for … his conspiracy theory that a secret cabal of reptilian humanoids is running the world. Simon Little
… has often been criticized for promoting conspiracy theories such as "birtherism," the theory that President Obama was not born in the U.S. Grace Segers

Examples of conspiracy theory in a Sentence

Conspiracy theories sprung up soon after the leader's assassination.
Recent Examples on the Web Why Princess Kate conspiracy theories are circulating People online have started cooking up theories surrounding Middleton's public absence. Grace Tucker, The Enquirer, 1 Mar. 2024 However, for the past 48 hours, conspiracy theories about the whereabouts of Kate Middleton have been shared wildly on X, the social media platform previously known as Twitter. Elise Taylor, Vogue, 29 Feb. 2024 Before the Instagram post, Biden uploaded his first-ever TikTok, which also appeared to poke fun at the Swift conspiracy theory. Becca Longmire, Peoplemag, 27 Feb. 2024 Meyers quizzed Biden about a conspiracy theory spread among some conservatives on social media that Swift and Super Bowl champion Kansas City Chiefs tight end Travis Kelce are part of an elaborate plot to help Democrats win the November election. Zeke Miller, Fortune, 27 Feb. 2024 Throughout the conference, racist extremists, some of whom had secured official CPAC badges, openly mingled with conference attendees and espoused antisemitic conspiracy theories. Ben Goggin, NBC News, 26 Feb. 2024 That’s led to conspiracy theories online that Google is intentionally avoiding depicting white people. Tom Warren, The Verge, 22 Feb. 2024 What To Watch For Georgia election workers Freeman and Moss filed a second defamation lawsuit against Giuliani in December after the attorney continued to make false claims about them that perpetuated the false conspiracy theory and maintained Giuliani did nothing wrong. Alison Durkee, Forbes, 20 Feb. 2024 At the same time, Mr. Trump gets the kind of unfiltered access to the airwaves that networks were, once upon a brief time, wary of giving a candidate notorious for fabrications and conspiracy theories. James Poniewozik, New York Times, 17 Feb. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'conspiracy theory.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1863, in the meaning defined above

Time Traveler
The first known use of conspiracy theory was in 1863

Dictionary Entries Near conspiracy theory

Cite this Entry

“Conspiracy theory.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/conspiracy%20theory. Accessed 19 Mar. 2024.

Kids Definition

conspiracy theory

noun
: a theory that explains an event or situation as being the result of a secret plot
conspiracy theorist noun
Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!