cyclic vs periodicity

cyclic is not a noun while periodicity is a noun.

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

cyclic (noun)	periodicity (noun)
	the quality of recurring at regular intervals

cyclic (adjective)	periodicity (adjective)
recurring in cycles
of a compound having atoms arranged in a ring structure
forming a whorl or having parts arranged in a whorl
conforming to the Carnot cycle
marked by repeated cycles