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

Local and national news The man who set himself on fire outside Trump’s trial had reportedly spouted conspiracy theories. —Andrew J. Campa, Los Angeles Times, 21 Apr. 2024

In the United States, the most popular conspiracy theory saw Fast and Furious as a plot by President Barack Obama’s administration to rein- state an assault rifle ban and implement new gun control measures. —Ieva Jusionyte, Rolling Stone, 16 Apr. 2024

The 22-year old Ben Brody sued Musk for defamation last fall, alleging that Musk pushed a conspiracy theory that falsely identified Brody as being involved in a fight between two far-right groups in Oregon. —Amrita Khalid, The Verge, 9 Apr. 2024

In some instances, Musk has promoted far-right conspiracy theories that have been debunked by news organizations. —Niha Masih, Washington Post, 8 Apr. 2024

Tomlinson’s recent comments about the Larry shippers is a sobering reminder about the real-world impact of the celebrity rumor mill and the current public appetite for celebrity conspiracy theories. —Meg Walters, Glamour, 10 Apr. 2024

The focus of the lawsuit is a series of tweets that Musk made last summer that promoted a far-right conspiracy theory that falsely linked Brody to an Oregon brawl between the Proud Boys and a local neo-Nazi group. —Amrita Khalid, The Verge, 9 Apr. 2024

The cases prompted speculation and conspiracy theories for more than a decade. —Michael Ruiz, Fox News, 9 Apr. 2024

The events have sparked rumors and conspiracy theories as the public tries to understand how or if they are connected. —Ashley Luthern, Journal Sentinel, 9 Apr. 2024

Word History

First Known Use

1863, in the meaning defined above

Kids Definition

conspiracy theory

noun

: a theory that explains an event or situation as being the result of a secret plot

conspiracy theorist noun