What is Conjuration?

Legal Definition
A swearing together. It signifies a plot, bargain, or compact made by a number of persons under oath, to do some public harm. In times of ignorance, this word was used to signify the personal conference which some persons were supposed to have had with the devil, or some evil spirit, to know any secret, or effect any purpose.
-- Bouviers Law Dictionary
Legal Definition
In old English law. A plot or compact made by persons combining by oath to do any public harm. Cowell. The offence of having cohference or commerce with evil spirits, in order to discover some secret, or effect some purpose. Id. Classed by Blackstone with witchcraft, enchantment, and sorcery, but distinguished from each of these by other writers. 4 Bl. Comm. 60; Cowell. Co.oper v. Livingston, 19 Fla. 693
-- Black's Law Dictionary
Legal Definition
Conspiracy; a criminal plot.
-- Ballentine's Law Dictionary