conspiracy vs conspiratorial

conspiracy is a noun but conspiratorial is not a noun.

Word	Noun	Adjective	Verb	Adverb
conspiracy	Yes	No	No	No
conspiratorial	No	Yes	No	No

conspiracy (noun)	conspiratorial (noun)
a plot to carry out some harmful or illegal act (especially a political plot)
a secret agreement between two or more people to perform an unlawful act
a group of conspirators banded together to achieve some harmful or illegal purpose

conspiracy (adjective)	conspiratorial (adjective)
	relating to or characteristic of conspiracy or conspirators