A theory seeking to explain a disputed case or matter as a plot by a secret group or alliance rather than an individual or isolated act.
- conspiracy theorist
(plural conspiracy theories)
- A hypothesis alleging that the members of a coordinated group are, and/or were, secretly working together to commit illegal or wrongful actions including attempting to hide the existence of the group and its activities. In notable cases the hypothesis contradicts the mainstream explanation for historical or current events.
- (dismissive) Hypothetical speculation that is untrue or outlandish.
- The phrase conspiracy theory is sometimes used in an attempt to imply that hypothetical speculation is not worthy of serious consideration, usually with phrasing indicative of dismissal (e.g., "just a conspiracy theory"). However, any particular instance of use is not necessarily pejorative. Some consider it inappropriate to use the phrase "conspiracy theory" in an attempt to dismissively discredit hypothetical speculation in any form.