hierarchy vs hierarchical

hierarchy is a noun but hierarchical is not a noun.

Word	Noun	Adjective	Verb	Adverb
hierarchy	Yes	No	No	No
hierarchical	No	Yes	No	No

hierarchy (noun)	hierarchical (noun)
a series of ordered groupings of people or things within a system
the organization of people at different ranks in an administrative body

hierarchy (adjective)	hierarchical (adjective)
	classified according to various criteria into successive levels or layers