preventative vs obstructer

preventative and obstructer both are nouns.

Word	Noun	Adjective	Verb	Adverb
preventative	Yes	Yes	No	No
obstructer	Yes	No	No	No

As nouns, obstructer is a hypernym of preventative; that is, obstructer is a word with a broader meaning than preventative:

Other hypernyms of preventative include impediment, impedimenta, obstruction, obstructor.

preventative (noun)	obstructer (noun)
remedy that prevents or slows the course of an illness or disease	any structure that makes progress difficult
an agent or device intended to prevent conception	someone who systematically obstructs some action that others want to take
any obstruction that impedes or is burdensome

preventative (adjective)	obstructer (adjective)
tending to prevent or hinder
preventing or contributing to the prevention of disease