circumference vs circumferential

circumference is a noun but circumferential is not a noun.

Word	Noun	Adjective	Verb	Adverb
circumference	Yes	No	No	No
circumferential	No	Yes	No	No

circumference (noun)	circumferential (noun)
the size of something as given by the distance around it
the length of the closed curve of a circle
the boundary line encompassing an area or object

circumference (adjective)	circumferential (adjective)
	lying around or just outside the edges or outskirts