pre-emptive vs preventive

pre-emptive is not a noun while preventive is a noun.

Word	Noun	Adjective	Verb	Adverb
pre-emptive	No	Yes	No	No
preventive	Yes	Yes	No	No

pre-emptive (noun)	preventive (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

pre-emptive (adjective)	preventive (adjective)
designed or having the power to deter or prevent an anticipated situation or occurrence	tending to prevent or hinder
	preventing or contributing to the prevention of disease