What is an agreement, manifesting itself in words or deeds, by which two or more persons confederate to do an unlawful act, or to use unlawful to do an act which is lawful; confederacy called?

conspiracy — (Law) An agreement, manifesting itself in words or deeds, by which two or more persons confederate to do an unlawful act, or to use unlawful to do an act which is lawful; confederacy. (Webster's 1913.)

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