Other forms: conspiracies
A conspiracy is a secret agreement between two or more people to commit an unlawful or harmful act. A person who believes that the government is secretly controlled by power brokers, in flagrant violation of the U.S. Constitution, is an example of a conspiracy theorist.
Conspiracy can also refer to the act of planning an unlawful or harmful act: Terrorists might be accused of organizing a conspiracy to overthrow the government. Conspiracy is ultimately from Latin cōnspīrāre "to agree or plot together, literally to breathe together." The corresponding English verb is conspire.