cyclic vs circular

cyclic is not a noun while circular is a noun.

Word	Noun	Adjective	Verb	Adverb
cyclic	No	Yes	No	No
circular	Yes	Yes	No	No

cyclic (noun)	circular (noun)
	an advertisement (usually printed on a page or in a leaflet) intended for wide distribution

cyclic (adjective)	circular (adjective)
recurring in cycles	having the shape or form of a circle
of a compound having atoms arranged in a ring structure	describing a circle; moving in a circle
forming a whorl or having parts arranged in a whorl
conforming to the Carnot cycle
marked by repeated cycles