| verb | engage in plotting or enter into a conspiracy, swear together “They conspired to overthrow the government” |
| verb | act in unison or agreement and in secret towards a deceitful or illegal purpose “The two companies conspired to cause the value of the stock to fall” |
| conspirative | adjective | relating to or characteristic of conspiracy or conspirators |
| conspirator | noun | a member of a conspiracy |
| conspiracy | noun | a plot to carry out some harmful or illegal act (especially a political plot) |
| cabal | noun | a plot to carry out some harmful or illegal act (especially a political plot) |
| machination | noun | a crafty and involved plot to achieve your (usually sinister) ends |
| machinator | noun | a member of a conspiracy |
| collusive | adjective | acting together in secret toward a fraudulent or illegal end |
| collusion | noun | agreement on a secret plot |