cheerful vs cheer

cheerful is not a noun while cheer is a noun.

Word	Noun	Adjective	Verb	Adverb
cheerful	No	Yes	No	No
cheer	Yes	No	Yes	No

cheerful (noun)	cheer (noun)
	the quality of being cheerful and dispelling gloom
	a cry or shout of approval

cheerful (adjective)	cheer (adjective)
being full of or promoting cheer; having or showing good spirits
pleasantly (even unrealistically) optimistic

cheerful (verb)	cheer (verb)
	become cheerful
	spur on or encourage especially by cheers and shouts
	show approval or good wishes by shouting
	cause (somebody) to feel happier or more cheerful
	give encouragement to