circumferent vs circumference

circumferent is not a noun while circumference is a noun.

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

circumferent (noun)	circumference (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

circumferent (adjective)	circumference (adjective)
closely encircling