a secret plan by a group of people to do something harmful or illegalconspiracy (to do something)a conspiracy to overthrow the governmentconspiracy (against somebody/something)conspiracies against the presidentconspiracy (to something)They were charged with conspiracy to murder.a conspiracy of silence(= an agreement not to talk publicly about something which should be made public)a conspiracy theory(= the belief that a secret conspiracy is responsible for a particular event)Oxford Collocations Dictionaryadjectivebig,great,larger,…verb + conspiracybe involved in,join,be part of,…conspiracy + nountheory,chargeprepositionconspiracy against,conspiracy betweenphrasesa conspiracy of silenceSeefull entrySee related entries:TerrorismWord Originlate Middle English: from Anglo-Norman French conspiracie, alteration of Old French conspiration, based on Latin conspirare ‘agree, plot’, from con- ‘together with’ + spirare ‘breathe’.Extra examplesHe’s the sort of person who sees a conspiracy around every corner.I suspected that he was involved in the conspiracy.Officials have uncovered a conspiracy to discredit the government.There is a conspiracy of silence about the killer.This action was part of a conspiracy to deceive the public.Who organized the conspiracy against the president?a conspiracy against the kinga conspiracy between the police and the right-wing partiescharges of criminal conspiracy and corruptionA lot of people subscribe to the conspiracy theory.He claimed there had been a conspiracy to overthrow the government.There had been several conspiracies against the president.There seems to be a conspiracy of silence on this matter.
See conspiracy in the Oxford Advanced American Dictionary