fewer vs comparative

fewer is not a noun while comparative is a noun.

Word	Noun	Adjective	Verb	Adverb
fewer	No	Yes	No	No
comparative	Yes	Yes	No	No

fewer (noun)	comparative (noun)
	the comparative form of an adjective or adverb

fewer (adjective)	comparative (adjective)
(comparative of `few' used with count nouns) quantifier meaning a smaller number of	estimated by comparison; not absolute or complete
	relating to or based on or involving comparison