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
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
Grace Segers Examples of conspiracy theory in a Sentence
Conspiracy theories sprung up soon after the leader's assassination.
Recent Examples on the Web
Tangent Over the weekend, Trump shared a post on Truth Social, boosting a baseless right-wing conspiracy theory that former President Joe Biden was executed in 2020 and replaced with a clone or a robot.
—Siladitya Ray, Forbes.com, 5 June 2025
Trump wished Biden well after the cancer diagnosis, but has continued to criticize his predecessor and share baseless conspiracy theories about him.
—Khaleda Rahman
shane Croucher, MSNBC Newsweek, 5 June 2025
Trump reposts conspiracy theory suggesting Biden is a robotic clone| RISING
Robby Soave and Lindsey Granger react to President Trump reposting a conspiracy theory about former President Joe Biden being replaced by a robot clone.
—The Hill, 2 June 2025
Now he’s been out-righted by the right with the conspiracy theory stuff.
—Ben Travers, IndieWire, 31 May 2025
See All Example Sentences for conspiracy theory
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Siladitya Ray, Forbes.com, 5 June 2025
Trump wished Biden well after the cancer diagnosis, but has continued to criticize his predecessor and share baseless conspiracy theories about him.
—Khaleda Rahman
shane Croucher, MSNBC Newsweek, 5 June 2025
Trump reposts conspiracy theory suggesting Biden is a robotic clone| RISING
Robby Soave and Lindsey Granger react to President Trump reposting a conspiracy theory about former President Joe Biden being replaced by a robot clone.
—The Hill, 2 June 2025
Now he’s been out-righted by the right with the conspiracy theory stuff.
—Ben Travers, IndieWire, 31 May 2025
See All Example Sentences for conspiracy theory
Cite this Entry
“Conspiracy theory.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/conspiracy%20theory. Accessed 13 Jun. 2025.
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