[1] : The Collaborative International Dictionary of English v.0.48

cahoot \cahoot"\, n. perhaps fr. f. cohorte a company or
   band.
   partnership; league; as, to go in cahoot or in cahoots with
   a person. usually used in the plural, and in modern usage
   often used to imply that the joint effort is unethical,
   shady, questionable, or illegal; as, a shill in cahoots with
   a pickpocket, to serve as a distraction. slang, southwestern
   u. s. --bartlett.
   1913 webster +pjc

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Cahoot, definition of term: Cahoot
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