Synonyms of conspirator
plotterA plotter is a person who secretly plans with others to do something that is illegal or wrong, usually against a person or government.
• the chief plotter behind the unsuccessful coup attempt
schemerIf you refer to someone as a schemer, you mean that they make secret plans in order to get some benefit for themselves.
• She is a schemer, my wee sister.
plotterintriguerconniverMachiavelliwangler (informal)slyboots (informal)wheeler-dealer (informal)
Thesaurus for conspirator from the Collins English Thesaurus