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

Yet figures like Yass and particularly Elon Musk — who has duct-taped himself, and his entangled financial interests to Trump’s transition team and many of their personnel and policy decisions — face little scrutiny from the same critics who level conspiracy theories against Soros. —Dewardric L. McNeal, CNBC, 5 Dec. 2024

Van der Linden also highlights the need for addressing conspiracy theories with specificity. —C.m. Rubin, Forbes, 2 Dec. 2024

Patel has pushed extensive conspiracy theories about federal government employees, Trump critics, the 2020 presidential election, the COVID-19 vaccine and more. —Rachel Barber, USA TODAY, 1 Dec. 2024

One of the most notorious cold cases of all time, the child beauty queen's bizarre disappearance and murder has inspired countless conspiracy theories. —Declan Gallagher, EW.com, 27 Nov. 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