Noun

• S: (n) confederate (confederate%1:18:01::), collaborator (collaborator%1:18:02::), henchman (henchman%1:18:00::), partner in crime (partner_in_crime%1:18:00::) (someone who assists in a plot)
• S: (n) collaborator (collaborator%1:18:01::), collaborationist (collaborationist%1:18:00::), quisling (quisling%1:18:00::) (someone who collaborates with an enemy occupying force)
• S: (n) collaborator (collaborator%1:18:00::), cooperator (cooperator%1:18:00::), partner (partner%1:18:00::), pardner (pardner%1:18:00::) (an associate in an activity or endeavor or sphere of common interest) "the musician and the librettist were collaborators"; "sexual partners"