preventive vs healthful

preventive is a noun but healthful is not a noun.

Word	Noun	Adjective	Verb	Adverb
preventive	Yes	Yes	No	No
healthful	No	Yes	No	No

preventive (noun)	healthful (noun)
remedy that prevents or slows the course of an illness or disease
an agent or device intended to prevent conception
any obstruction that impedes or is burdensome

preventive (adjective)	healthful (adjective)
tending to prevent or hinder	conducive to good health of body or mind
preventing or contributing to the prevention of disease	free from filth and pathogens